Gabrielle has some good action in book 3, QOTD, so you might be interested in that.
I love it when ppl play up both genders in their fanart of her. Especially her miffed reaction to being called Mom still!

I’m not really knowledgeable about transgender issues, but it is an interesting headcanon re: Gabrielle.
But I’ll try anyway a little! Maybe when she was mortal she might have preferred being a man because alot of power and freedom went along with that gender at that time. I headcanon that her marriage was an arranged one, not out of love. She doesn’t seem to have negative feelings about her own body in its femaleness. She wants all the men in town to sleep with her as a power-thing, as an ultimate fuck-you to her ungrateful and unloving husband.
I don’t think she resented her children so much as she didn’t really reach out to them when they were young, bc so many did not survive to adulthood that, having known them better, their loss would have been more painful for her. Maybe she resented the children that survived because they didn’t feel loved by her, and sided with the Marquis; so by the time they were old enough that she could trust that they would continue to adulthood, they had already become so much like him that she didn’t like them as people, either (Lestat being the obvious exception).
She might have been bisexual as a mortal, too, and felt trapped by her arranged marriage.