Our 2 girls are 14 months apart. I have mixed feelings about the fact that DD13 moved into DD14's grade several years ago. The positives? DD13 left a toxic 4th grade and moved into a 5th grade that offered her more academic options. She was challenged - for a while. The negatives: Sometimes kids ask DD14, "Is your sister really smart?" and insinuate that DD14 is not. Socially it's been hard. Party invitations, sleepovers, get tricky. Your kids are brother and sister so it may not be part of the equation. Emotionally - DD14 feels "stupid" although she actually gets the better grades. She is hard working and studious and does not understand that those traits may get her further along than her younger sister who doesn't study a bit.
Perhaps other parents have figured out how to make this work more smoothly. We read posts on the forums and other gifted websites. We make sure each girl has her own clubs and electives. Long ago DD14's kindergarten teacher asked us if we were interested in a grade skip for DD. We didn't even entertain the notion as at that time we were pretty clueless about acceleration. However, DD14 seemed absolutely happy with her school situation, and DD13 just screamed unhappiness and misery.
As a side note, DD13 could easily move up another grade as she still slides by without an effort. That would be horrific for DD14. We would never make that decision. It could work for some families, I suppose.
