Alright, Hua Mulan. In most traditions of the story she was a resident of the state of Northern Wei, the longest-lasting of the Northern Dynasties (386-535CE) of the Northern & Southern Period (420-589CE). There are, of course, other tellings that put her in the Sui/Tang period, and certain others that put her in a nebulous “sometime in ancient and faraway musical Chiiiiina”… but most tellings put her in Northern Wei.

This creates from the outset some very interesting and problematic issues with the Disnified version. For one, though Mulan and her people are indeed called to serve against invaders, it’s never specified in the Ballad of Mulan which invaders they’re talking about, and it certainly never talks about “Get[ting] down to business to defeat the Huns/Xiongnü”… because, well, the “Huns” were already there, in Northern Wei… as its emperors, officials, and population. Northern Wei was a Tuoba xianbei state that had partially sinified itself… but was still viewed by the Southern Han Chinese (of the Liu Song and Southern Qi Dynasties, respectively) as themselves the barbarians. From the Ballad of Mulan:

昨夜见军帖，可汗大点兵.

trans: ““Last
 night 
I
 saw
 the 
draft
 posters, The 
Khan
 is
 calling 
many 
troops."

From later on in the poem, after Mulan and her army has won the war:

归来见天子，天子坐明堂。策勋十二转，赏赐百千强。可汗问所欲，木兰不用尚书郎，愿驰千里足，送儿还故乡。

trans: “On
 her 
return 
she 
sees 
the 
Son 
of 
Heaven, The
 Son
 of
 Heaven
 sits
 in
 the
 Splendid 
Hall. He
 gives 
out
 promotions
 in
 twelve 
ranks And
 prizes
 of
 a 
hundred 
thousand
 and
 more. The 
Khan
 asks
 her
 what
 she 
desires. “Mulan 
has 
no
 use 
for
 a
 minister’s 
post. I 
wish
 to 
ride 
a 
swift 
mount, To take 
me 
back 
to 
my 
home.”

The Son of Heaven is the Khan, and the Khan is the Son of Heaven. Flibbity-flibbity-floo. The fact of the matter is that especially northern Chinese history is far, far more of a cultural and ethnic melting pot than quite a few realize, or would care to admit.

So these invaders could have been the Chinese themselves, or the Tibetans, or Tuyuhun, or the Ruanruan Khannate (which seems a likely choice)… but the one thing they were not were the Huns/Xiongnü… because neither existed in any meaningful capacity by this point. But ah well, I’m getting off topic…

We can infer quite a bit about the era she lived in and the likely consequences of her actions by the reactions of those around her – both her family, and later on the soldiers she’s come to lead in combat:

可汗大点兵。军书十二卷，卷卷有爷名。阿爷无大儿，木兰无长兄。愿为市鞍马，从此替爷征。

东市买骏马，西市买鞍鞯，南市买辔头，北市买长鞭。旦辞爷娘去，暮宿黄河边。不闻爷娘唤女声，但闻黄河流水鸣溅溅。旦辞黄河去，暮至黑山头。不闻爷娘唤女声，但闻燕山胡骑鸣啾啾。

万里赴戎机，关山度若飞。朔气传金柝，寒光照铁衣。将军百战死，壮士十年归。

trans: The 
Khan 
is 
calling 
many 
troops. The 
army 
list 
is 
in 
twelve 
scrolls, On
 every
 scroll 
there’s 
Father’s 
name. Father
 has
 no
 grown up
 son, Mulan 
has
 no 
elder 
brother. I
 want 
to
 buy 
a
 saddle 
and
 horse, And
 serve
 in
 the
 army
 in
 Father’s 
place.”

In
 the 
East
 Market 
she
 buys 
a 
spirited
 horse, In
 the
 West 
Market 
she 
buys 
a 
saddle, In
 the 
South 
Market
 she
 buys 
a 
bridle, In
 the
 North Market 
she 
buys 
a
 long 
whip. At 
dawn
 she 
takes 
leave
 of 
Father 
and
 Mother, In
 the
 evening
 camps
 on
 the
 Yellow
 River’s 
bank. She
 doesn’t
 hear 
the 
sound
 of
 Father 
and
 Mother
 calling, She
 only
 hears 
the 
Yellow 
River’s 
flowing
 water 
cry
 tsien
 tsien.

She
 goes
 ten 
thousand 
miles 
on 
the
 business 
of
 war, She 
crosses 
passes
 and
 mountains
 like 
flying. Northern
 gusts 
carry
 the 
rattle 
of
 army
 pots, Chilly 
light 
shines 
on 
iron 
armor. Generals
 die
 in 
a 
hundred
 battles, Stout 
soldiers 
return 
after
 ten 
years.

She's not sneaking off in the middle of the night on a stolen horse with a borrowed saddle. She says to her parents, "hey, Dad can't go fight, I'm gonna go buy a horse and go off to war." And her parents don't try to stop her. Yeah, sure, they're sad and all, but such is life in a time of war. What they're not terribly concerned about is the fact that she's a girl.

Because the historical Mulan isn't some pale-face beauty (ok, well she is, but that's not her only or even most important quality.) The Ballad paints Mulan as more of an Ellen Ripley-esque certifiable badass. There's no "I'll Make A Man Out of You" montage in the poem, because she is beating the snot out of her fellow soldiers from day one. Even the Khan take note:

On
 her 
return 
she 
sees 
the 
Son 
of 
Heaven, The
 Son
 of
 Heaven
 sits
 in
 the
 Splendid 
Hall. He
 gives 
out
 promotions
 in
 twelve 
ranks And
 prizes
 of
 a 
hundred 
thousand
 and
 more. The 
Khan
 asks
 her
 what
 she 
desires. “Mulan 
has 
no
 use 
for
 a
 minister’s 
post. I 
wish
 to 
ride 
a 
swift 
mount, To take 
me 
back 
to 
my 
home.”

Moreover, there's no mid-war gender-reveal. Instead, she reveals she "he's" been a "she" these past 12 year only after the war, and voluntarily to her brothers-in-arms:

脱我战时袍，著我旧时裳。当窗理云鬓，对镜帖花黄。出门看火伴，火伴皆惊忙：同行十二年，不知木兰是女郎。

雄兔脚扑朔，雌兔眼迷离；双兔傍地走，安能辨我是雄雌？

“I
 open 
the
 door
 to
 my 
east 
chamber, I
 sit 
on 
my 
couch 
in 
the 
west 
room, I
 take 
off 
my 
war time
 gown, and 
put 
on
 my 
old time
 clothes.” Facing 
the 
window
 she
 fixes 
her 
cloud like 
hair, Hanging
 up
 a
 mirror 
she 
dabs 
on 
yellow
 flower 
powder. She 
goes 
out 
the 
door
 and
 sees 
her
 comrades. Her 
comrades 
are
 all 
amazed 
and
 perplexed. Traveling 
together 
for 
twelve
 years They
 didn’t 
know
 Mulan
 was 
a 
girl.

“The 
he hare’s 
feet
 go
 hop
 and
 skip, The 
she hare’s 
eyes 
are 
muddled 
and 
fuddled. Two 
hares
 running
 side
 by
 side
 close 
to 
the 
ground, How 
can 
they 
tell 
if 
I 
am
 he 
or 
she?"

Her comrades are all sorts of "amazed and perplexed" that this ultimate badass was a smokin' hottie the whole time, yes, but she obviously believes that there's no danger in letting them know. No punitive action is going to be taken against her... certainly nothing like Shen threatening her at swordpoint for the crime of saving his live while having gross girl-germs.

This hearkens back to the fact that Northern Wei, for all it desperately wanted to be, was not totally culturally Chinese... it still had many of the social and gender norms inherited from the Asian steppes and their formerly nomadic traditions - traditions like boys and girls should be trained to fight and defend their home, they should all be capable with the horse, bow, and sword... and that it was not entirely unheard of for men and women to serve alongside one another.

Moreover, Mulan in all her tellings serves as a paragon of the Chinese Virtue Above All Other Virtues: filial piety. Sure, she's a girl, but her dad has no grown sons, and he can't effectively serve his lord... she she helps him by serving the khan on his behalf. That is hardly something to be punished in Chinese value systems.

---

This does change - as does the story itself - if it moves to a different time period. Chu Renhou's The Sui Tang Romance moves the tale of Mulan up in time to the Tang overthrow of the Sui, ca. 618 CE. moreover, it was written in the Qing Dynasty of the late 17th century. Now, Chu borrowed heavily (and copied verbatim in more than a few places) from the earlier (pub. 1633) Forgotten Tales of the Sui Dynasty. Nevertheless, it is very very focused on the idea of suicide or ritual defacement to establish its female characters with virtue and honor equal to men. Thus, in the tale of Hua Mulan, we first get a twist of her being found out, but by the warrior-princess Dou Xianniang, who tries to recruit Mulan as a man, but then pledges to keep her secret and becomes sworn sisters. But by the end of the tale, Xianniang's father is captured by the soon-to-be-Emperor Taizong of Tang, and they surrender themselves to suffer his punishment in his stead. Taizong sees this as a supreme act of filial piety and (in the book) commute the death sentence of Dou Jiande (in reality, no, Dou was executed), and Mulan sent home to relocate her parents. Harsh reality sets in, however, when she discovers that her father has died, and her mother remarried. Worse comes to worst when Taizong's ally the Göktürk Khan summons her to his capital to become one of his concubines... at which point she decides to commit suicide rather than suffer such a fate. From Martin W. Huang:

Her suicide is particularly baffling since at the time she is not in love or engaged with anyone and since she is only half-Chinese (her father Turkish, but her mother is Chinese). Hegel provides the possible explanation that this is intended to be a loyalist message: “even a half-Chinese woman would prefer death by her own hand to serving a foreign ruler.” Also worth mentioning here is Mulan’s explanation for why she has masqueraded as a man to join the military: “Feeling ashamed that there were not many loyal subjects and filial sons among men, I decided to take the risk to dress myself as a man.” Here Mulan is apparently blaming the incompetence of men as one of the reasons that she felt compelled to join the military. In other words, there would have been no need for her to do so if men had been competent enough to fulfill their duties.

Yet even in this telling where her femaleness does result in tragedy, it's again not the emperor or a military officer threatening to cut her down for her womanhood... indeed, though Taizong was prepared to have her and Xianniang executed, that was because they were captured enemy combatants, not because they were women. (Hell, Taizong's own sister, Princess Pingyang, was leading her own anti-Sui "Women Peasant Army" at this same time... and I should note that the Tang rulers were themselves semi-Turkic). Rather, the issue is having her fate taken out of her own hands as a result: going from being a respected army officer, to being the concubine of a foreign lord.