[mangoandmimi]

I think you need to remove the penthouse and put the bedding from there into a house - otherwise she very likely won’t change house. Yes it’s stressful but they cope fine if it’s one change at a time - and it’s better in the long run.
Cardboard boxes are fine but if you want a new one you’re best off looking at Guinea pig ones as most hamster ones are a bit small for syrians. The doors are big so either partially bury the house or like cypher said a log bridge. The wooden corner houses are good as is the wooden ferplast one with the four holes as the window but anything will do really.