Here's a suggestion based on my experiences........
Wednesday is the best day if you can work it out that way..... well it worked for me. Having an easier day, and I don't know that 30 minutes is enough to make it an easier day, in the middle of the week makes it a lot easier to get through the week. It allows for full energy practices on Monday and Tuesday with Wednesday as a recovery day, and the rest of the week can go full energy because of the benefits of that rest.
Resting is more effective if it's done to maintain an energetic kid, and less effective if it's used as an energy crash recovery tool. Keep that in mind if you're thinking of using "short days" on an as needed basis. Sure it can work, but your child needs to learn to realize she's getting pooped out and let you know.
Just a short lecture here, for those who think practice time is too valuable to cut in favor of rest.......
Sure, in a perfect gymnastics world, I'd say gym time comes first, and expect parents to adjust their own and their child's schedule outside the gym to allow for adequate rest time, and school issues would have to resolved with the cooperation of the school staff.
Yeah, there's programs that have kids in the gym for 35 ish hrs a week, but those programs usually have a coach in the center with a reputation for training high level kids. They collect kids from the region and across the county who want that sort of experience, with parents who're willing and able to shell out a modest person's annual income to pay for gym time, privates, tutors, physios, and well, whatever else helps their Susie, who at last can kip like a champ, advance just a little farther.
But this is not a perfect gymnastics world, well for most of us, and you just have to get a little creative and do the best you can with what you have. A good start is realizing the kid in front of you is a complete person who has needs in many aspects of her life, and to get the most out of the kid........
Well let me sum the above paragraph up.
You get more gymnastics out of a kid when they have no unfulfilled needs. Figure out how to help the total child, and the gymnastics gets a lot easier...... for you, and the child.
And remember, it's never easy, but it's usually a lot of fun.