We are 4 weeks into a skip from 4th to 6th and it is going great. I can't see having made any other decision. It helped that my daughters best friend was already in 6th grade. I see her doing homework for the first time. She doesn't like it, but she is still making lots of 100s, though she has gotten something wrong on a couple more quizzes than in the past. She is adjusting to the fact that she is not done with everything before she leaves school.
We are not really interested in her starting high school early. So, we will likely do a pre-high school gap year/homeschool year and maybe have her do some type of research project.
