Thanks again for answers!
It is the Ferplast Maxi Duna Multy
It looks like they are fine for now, but I will be on the lookout for signs of them not getting along!
I have lots of bendy bridges, houses, tunnels and other toys for the big cage that I think will be perfect for them.
My mom also says that she doesn't care if they have to be separated, just because we can give them a much better life then they had before we got them! She is so sweet with these little creatures and loves to cuddle with my other dwarf hamster, and she checks in with all of them several times a day.