After dealing with a few families that drove me crazy, I can see why you would want to make it work for a family that you really like. If you can find a compromise that works for both you and her than go for it. If you think they will screw you over just fill the spot now.

I totally understand that we need to look our for ourselves first but....what kind of world would we live in if we all just looked out for ourselves. I like to find a happy medium....looking after myself but also taking others into consideration. In the long run, it might be better to have this family than some other family who you won't like as much. It's a risk only you can decide if you want to take! Good luck with whatever decision you make