📚 Rolling release distro for beginners

I have a question, it may seem strange but here goes:

I have a nephew who uses Linux but doesn't have much of an ability to manage his own system and he comes back from time to time to get help. So I thought it would be better to have a rolling release distro, but not as cutting edge as Arch, which is what I use together with Slackware. What distro do you recommend?

I've been completely out of distrohopping for years!!!