"How long before you were comfortable with your decision?"
I'm a bit of a worry-wort, so even with overwhelming evidence that her skips were extremely successful, every once in a while I'd still have an irrational worry crop up.
By the the middle of her first post-skip school year we knew she was where she was supposed to be. By the end of her third post-acceleration school year, she was being evaluated for another grade skip - so certainly by then we must have been comfortable with the first one...
Best of luck,
--S.F.