Yes, Aquinnah would be for a girl. I could call her
Quinn sometimes but she'd have a longer, more feminine name to fall back on. I pronounce it ah-KWINN-nah whereas I pronounce Aquina more like ah-KEE-na, but I've been to a place named Aquina, pronounced like that. I also like Aquinna pronounced like Aquinnah.
Yeah, Aquinnah is a place that was named by Native Americans as far as I know. It means "land under the hill".
I like
Thora Birch, too.
Thora Willow is pretty. I like
Thor for a boy, but only with an English pronunciation. For some reason I dislike the Scandinavian one in which the Th is pronounced as a T.