We have been dealing with this this year. After homeschooling both kids last year, my daughter started 1st grade this year at a magnet school. Truthfully, it has not been an easy transition. My son (3rd grade) is still homeschooled, and he really misses his sister. She loves going to school, and this particular school has been a really great fit for her.
Personally, I do not love having one in school and one homeschooled; I feel like we do not get the full benefit of either one. We have to adhere to the school schedule, and always have to be back in time to pick her up from school, so we can't have the leisurely field trips that we took last year. We did pull her out for a week after Thanksgiving to go on our family vacation that was planned before we decided to try this school, but in general, we have to work around the school calendar now.
We try to focus on the positive, and I stress that we should be happy for her because she is happy at school. I don't know if we will continue this schedule next year though. My son was accepted at this same magnet school, and now we have to make another tough decision. He is adamant that he does not want to go, he wants her to come back home next year. I change my mind about what to do daily. I am tuly torn about the issue.
Hmph. I'm sure I didn't make you feel any better. :-( Sorry! Maybe someone else has been dealing with this better and we can both get some tips!