Which tablet to buy for kids?

[fandemic]

My son has just turned 9 and wants to use his birthday money to buy an Amazon Fire tablet for around £50. I've been reading reviews which are ... not amazing. And also i hate Amazon for ethical reasons so am not thrilled about the prospect of being locked in to parting paying them money. I'm wondering about alternatives. Is it possible to get a good tablet for kids for

We’ve got a Samsung one (not sure which model, sorry) and my 9yo daughter uses it with ease. I bought a decent case and a screen protector for it.

Following with a very similar question and budget. I just bought a Lenovo Yoga used on ebay for £50 and it's not able to run Google Family Link, which I now realise means it won't work for us. No returns either so I'll have to resell it 😢.

Google Family Link sounds very useful so I'm now looking for something that'll run that, I think it needs to be Android Lollipop or higher.

We've had an ipad on loan which needs to be returned very soon, it's been OK but I hate Apple and the parental control possibilities aren't great at all.