I've been in a similar situation before. Be prepared for divorce. To her, if you don't marry in the temple, she will probably do it after you die anyway. Yes, those of us in the hospital work longer and harder days than most people with 9 to 5s, but we still have off days.
Put that in perspective before you try to equate your struggle to his. Their thinking is something like this. She can never hang out on Sundays because she apparently spends the entire day at church. He could never tolerate my work schedule, so I became a stay at home mom. That's one great thing about the internet and blogging That is exactly how I feel. They value femininity, motherhood, and masculinity in men.
My husband has gone from proselytizing and thinking he knows it all to a real spiritual seeker, albeit with a strong testimony in the church. He's currently working in the ER and waiting to start his residency. You will always be second place. He's been in the medical field for over 16yrs and I didn't have a problem when we were dating 6yrs ago but since he proposed 2yrs ago I've been feeling very unsecured. He can't make a mental switch easily to adjust to our pace of life. And if you can make it to the Tree of Life and still be with your partner, guess what. This is not about either of you individually. No where did I say, nor I think indicate, that I thought this wasn't a complex issue, or that this girl is a caricature. Just know that she has been indoctrinated to believe that she wont reach the highest level of heaven if she isn't married in a Mormon temple to another Mormon.
Having said that, I believe strongly that it takes a special individual who can remain active in the church and have a non-traditional marriage. So I am at my dating prime. To others making this consideration, I would certainly suggest that you converse with your Father in Heaven about this important choice. She needs to be, and maybe she will get there.