This is a multi-layered issue that requires some 'deeper-drilling', lol. First question, who's idea was it to move-in together? If she brought it up then that's her exposing a very sensitive part of herself and be very careful how you answer/proceed. If this isn't handled properly, you could taint the relationship entirely...women don't take rejection on this deep of a level very well at all. (As an aside, I did a quick experiment w/a girl I was seeing casually just to see what affect it had on her...for a couple of sessions I decided to NOT have an orgasm and made sure she had as many as she desired. When I felt it was time to be done and I hadn't finished, she became confused, then obsessed and then almost angry like I rejected her or something was wrong with her or her pussy...it was very interesting to say the least)
Anyway, these next few steps/responses that you're facing are hugely important to your future as a couple...remember, women DO NOT think the same way that we do, there's always a reason/test. Take, for example a woman who's in a loving, committed relationship all of a sudden decides to get a boob-job...now her partner is completely happy the way she is and supports her fully in whatever she decides. She will make the assertion that getting the procedure done is to enhance the relationship, but it's truly for her and whatever her motivation is. I've known many an ex-husband that's still paying-off his ex's surgery...women are more cunning/calculated than we can ever imagine...so tread lightly, my friend