I agree both are great rounds and will serve you well for what you want to do. I agree with PapaD that the 25-06 has the edge. Then you threw in your 12 year old daughter and I changed my mind back to the .243. A 25-06 would most likely be too much gun for most 12 year old girls (or boys)
The .257 Roberts might be a good compromise but because of the recoil and chance your daughter would be hunting (and I really hope she is) I would go with the .243.
Thanks guys,
I think the .243 for the first deer rifle experience will be the best introduction. I like the idea of a heavy barrel version that helps reduce recoil as well.