Without being able to directly answer your question, I think it's worth making a distinction between aristocratic noblewomen and peasants. I don't have any sources on hand, but it seems that the condition for women, especially surrounding arranged marriages and divorce (or the lack thereof) were vastly different in the fields than in the estates. Women in village communities had much more economic power and independence than aristocratic women. noblewomen, pretty much from the Heian period on to the Meiji period were at the mercy of their father and husbands, barring nunnery.

There's also a geographic distinction between Eastern and Western Japan. Western Japanese village societies tended to be more matriarchal than in the East.

It might be a good idea to go back before the Heian period, to pre-Buddhist Japan (although there are very few sources) to see the greatest change in women's influence, as early Shinto had women in some of the highest religious positions if I'm not mistaken. Another significant change in women's status that I'm more familiar with is right after the Meiji restoration, when certain moral norms of aristocratic life began being encouraged in the farming classes. This includes arranged marriages (which weren't the norm before) and ideas of chastity/monogamy and total obedience to one's husband, which in a largely communistic village context, would have seemed absurd a few generations earlier.