My DD was also a Kindergartener on L4 team & did very well with the transition. I think she only did 10.5 hrs though to start. She loves being in the gym, and when she's not, she's doing handstands & floor routines at home. I made sure she had plenty of water with her at practice, fed her something right before practice, and gave her a snack (granola bar, cereal bar, piece of fruit) to keep in her gymbag/locker for a quick pick me up if needed. made sure dinner was ready for her either in car for way home or as a soon as we got home. Homework, the bulk of it was done before gym, I usually left any reading for PJ's & bedtime together as a quiet time activity. You would think that after being in the gym a couple hours at night/couple times a week they would be tired and go right to sleep...most are oppostite (like mine) and are extrememly hyped up when they get out of practice. We tried to stick to the dinner, bath, PJ's and reading in bed routine....it seems to work! DD also did Daisy scouts and teener ball. Hard to squeeze in, but we did to allow her to experience other activites as well. It's hard this year because now she is a L5 and practice is now about 15 hrs, so I did have to put the kabosh on field hockey this season. School starts this week for us so I'll let you know how the transition goes for us, but her new gym has earlier practice times and no 4 hr practicies, they are max at 3 hrs so I am liking that.