Hey, I too am in the match like you. But I thought I would share some advice I got from a senior friend of mine. She said two things:
1. Start your rank list from the bottom, or places you would not want to go.
2. Make a rough list, nothing set in stone, but how you 'liked' them.
3. Go over the pros/cons, what matters to you and try to arrange them.
After this, I was confused and it all looked the same. Then she said do this, take two programs, say number 5 and 6 on your list. If you were to match at number 5, would you feel you would have missed out on number 6? If yes, then rank 6 higher. It sorta comes down to the 'gut'. I tried the pros/cons, and it didn't work so well. Other things, like family ties, where you would like to live, huge city vs suburban all factor in. What I see above is you should discuss this with your girlfriend. From what I know, Comer has a very strong ped hem/onc setup. I have a friend who is a research nurse there in hem/onc. He can't stop talking about it!