If you have no reservations about her being trans, then go for it. Just make it clear that it would have to be NSA and cut it off if either of you develop feelings.

People in here are telling you not to have sex with friends. I don’t see a problem with it. I have friends I’ve slept with and it was fun. However...

Not everyone can do FwB without getting romantic feelings or messing things up. So ask yourself if that’s going to be an issue for you. There is always a possibility for things to change or get awkward.

It wouldn’t be exploitative. This is where you need to take her seriously and why she said stop treating her like a child.