Personally I would leave her in the Hamster Heaven. The large front door shouldn’t be under estimated! And if she is happy and settled in there. It would also be a big change from a barred cage with front access to a solid sided cage with top access. An upgrade can be a positive thing sometimes but maybe it’s more a case of if it ain’t broke don’t fix it and the HH has plenty of floorspace for a dwarf hammy.
With an empty maxi duna you may be tempted to look at filling it with another hammy
