TL;DR: Was there really 2 separate "crusades" in 1212 that were led by and mostly composed of kids? Some say yes, other say no as "kids" actually meant "poor peasants", don't know who to believe. Also dead people apparently can write.

Warning: poor grammar ahead

I like to pretend that I'm somewhat well read on the events of the first, second & third crusades since I studied these in college, but my understanding of what happened afterward is at best muddy and at worst full of /r/badhistory.

Still, I always believed that in the year 1212, two 12 years old shepherds, one leaving from France and the other from Germany, each assembled a group mostly composed of kids by preaching in their respective country.
These groups then spectacularly failed to reach Jerusalem, the one from Germany losing around 65% of its 20 000 members while crossing the Alps and the french one ending when the 30k or so kids composing it were told to go back home by Philip II
According to a french monk, after this there was 7000 or so kids on the initial 30k who decided to go ahead anyway with that whole "going on a crusade thing" and they supposedly end up being made slaves on the boats of two rich french merchants who told them that they'd help them reach Jerusalem, a few of them died when 2 of the "expedition's" 7 boats crashed during a storm and the remaining kids were then sold.
From my understanding that last part widely recognized as having never happened since we only have that one monk's writing mentioning it.
(Weird thing I just realized, this story is said by some to have been written between 1260 & 1295 by Alberic of Trois-Fontaine, but he died somewhere around 1252 from what I can see.)

But now I'm reading a little more on it and it seems that no one agree on what really happened or even if it happened at all (see the wikipedia article on this, which I may have used to refresh my memory while writing this). Could anyone shed some light on this for me please?