My dd12 skipped 5th and is now an 8th grader. She turned 12 just a few weeks ago. We don't have any experience with skipping a later grade than that, though.
I'd say that socially it has worked quite well in middle school for her to be one of the youngest, though. She fits in a lot better with the kids in her current grade than she did with the kids in her grade pre-skip.
If your dd is already attending class with kids in the older grades for some of the subjects, it might make the social adjustment easier as well.
