Prior to my conversion experience (I was a dissenting Catholic who became a faithful Catholic), I was firmly pro-choice. After this experience, I recognized the need to bow to the Church’s authority, but it took me several years before I could comfortably say that I was pro-life. There was a long period of transition, during which I was honestly trying to see where the Church was coming from and the problem was that I had some well-meaning intentions that led to my being pro-choice.
I’m saying this to make the point that not everyone who has a difficult time with the abortion issue is necessarily a bad Catholic, or has a completely skewed value system. HOWEVER, in my faith journey, and I believe in anyone’s (if they are honestly seeking the truth), I came to a point where I realized that being pro-choice was utterly incompatable with following Christ, specifically as a Catholic.
So I guess I would look at it this way. Is this woman like I was, growing in her faith, and gradually coming to terms with a whole new way of looking at a topic that has been drummed into her head for years? Or is she really set in her belief and not likely to change? I believe that a person who is staunchly pro-choice can only be this way if they also have some other major theological issues that might be big impediments to a good relationship with a Catholic.
Is she Catholic, btw? Personally, I have found that the differences between myself and pro-choice (and therefore usually otherwise dissenting) Catholics are HUGE, and I would probably not connect well enough with someone like that to fall in love with them. I do think that a pro-choice position is definitely cause to consider the future of the relationship. It would be harder for me to say that if it was an isolated issue - but I have yet to meet a pro-choice person who otherwise agrees with so many of the other values I hold dear.
May God bless your discernment.