You don't sound horrible, you sound concerned.

And TBH, I'd be concerned too.

Yes, some of what you've described isn't necessarily a problem but put it all together and they sound like kids who will have a few problems integrating into another community - which I know is what you're worried about.

I have absolutely no idea what to suggest because it sounds as if you've tried a few things like encouraging them to get out of the house and it's not working.

Maybe for one of the days you could say, "right, tomorrow there's no TV, no playstation and no playing with DD's toys ... you come up with some ideas of what you want to do." See if that works and maybe your mum could start doing something similar too - have a few days where they need to come up with stuff and gently tell them that although they've not been allowed to do many things before, they're bigger now.

I think with the peeing thing, you've got to come up with some consequences. How's your mum on discipline?

I know exactly what you mean - my nephew is a lot younger (about 10) but he's a bit similar in that a lot of what he does (or doesn't) isn't age appropriate and I worry about how he's going to get on in the world.