To have changed our little boys routine

[Moomoomango]

My son is in foundation and has been getting quite tired lately (the sort of "don't you dare say I'm tired" but having meltdowns and anger and overstimulated hyperactivity kind I'd tired).

He's been going to school 5 days a week then has swimming one evening a week and visits my mum one afternoon a week (school pick up until around 7) and my mother in laws another afternoon same hours. It's not needed for childcare they just enjoy having him.

We decided he probably needs more down time so have said we'd like to change so the grandparents swap alternate weeks so he's only out one evening a week plus his swimming night.
We always visit both sets of parents at weekends too.
My mother in law is very upset about it and has said she's going to be away most weekends (start of a new sporting season) so she'd only be seeing him once a fortnight.

Aibu to have changed this? I don't want her to be upset but she's really not taken it well. However i want to stand my ground and give my son chance to relax & play and play with his little brother and generally see him!

[Stripeyblanket]

She'll come round. It's for the benefit of your child. See how it goes for a few weeks and if it doesn't make a difference then perhaps you can switch it back.
Or could she not come for an hour or two after school where your DC is in his own home and surroundings and therefore possibly calmer and less stimulated?