Yeah! So surprise surprise going into the series I thought Haku was canonically a girl plus I remember watching the forest scene when I was younger and for whatever reason Haku just kinda stuck with me. Of course when it was revealed haku wasn’t a canon girl I was like oh whoops haha but even after I just kinda kept using she/her? Right after Haku died in the anime I already had an AU in mind where she lives and joins konoha etc etc but as I was developing it I realized that if I kept haku as a guy then the male-female ratio of the characters in the konoha 13 would be even more uneven then before so I just made the ultimate decision that she would be a girl in my au and that just kinda bled into my overall perception of the character haha long explanation sorry