Gym mums - tumble mat thickness ?

[Didiplanthis]

Im looking to buy a new tumble mat for my 8 yr old as hers is too small. I'm confused about thickness. She's moving towards aerials and flicks and so thick is good but if it's too thick will it be unstable for hand/foot steadiness ? I'm looking at a 6cm one but most seem to be 5cm.

what surface is she going to use it on?

Wooden floor with carpet mat. We have non slip matting to go under it.

We use Cannons mats for high impact exercises. One for indoors and one for outdoors! They're 6cm, but quite sturdy, good quality pvc, in addition. We have a thinner mat for other stretching exercises.

5cm or 6 cm would be fine. We have one like this (although not 8ft!)
m.ebay.co.uk/itm/Mirafit-8ft-Large-Folding-Exercise-Gymnastics-Floor-Mat-Gym-Crash-Tumble-Landing-/400823635329?_trksid=p2385738.m4383.l4275.c10&_mwBanner=1