I'm ftm and my gf is mtf and she has earlier said that she doesn't want to take HRT as she's afraid of how it would affect our sex life (both of us are totally okay with what we have, so bottom surgery isn't anything for either of us) But recently (like two weeks ago) she told me that maybe she do want to take E and we haven't really talked as much about it as I would have wanted (I'm not against her taking E, I want her to feel good, I just don't know what to expect) and I currently feel like I can't bring it up in any conversation without it seeming like I don't want her to. I just don't know what/how things would change like we like sex as it is and we don't want it to change, we also want kids at some point and I feel like I know nothing and how E would change her/her body (other than the more obvious things like breast growth and some fat redistribution)

What can I expect? How can I talk to her about it without me looking/being an ass? How would/could sex change and what can be done to keep it like it is?