How could the Doctor go back and visit young Amy from "The Eleventh Hour" when the timeline those scenes took place in doesn't exist any more. There never was an Amelia sitting on her suitcase in her garden once she got her parents back. That was kind of the whole point of the end of "The Pandorica Opens".
More importantly, we see in "The Big Bang" that she didn't wait outside all night, as in the time rewind the Doctor went outside, picked her up off the suitcase, put her to bed, and told her a story. In the rebooted universe, she spent the night snug in her bed.