As the others have said you can't go far wrong with lots of bendy bridges, for free cardboard boxes, egg boxes & cardboard tubes all make great toys.
Small terracotta flower pots are good too, you can half bury them & hide food or treats in for them to dig out & it's a good surface to help with wearing down nails.
The sea grass tunnels (available from Amazon) have been very popular with mine as have coconuts.
A good size fairly deep sand bath is pretty much an essential if she doesn't already have one, you can use large glass jars or just a plastic box, my current hybrid has a large plastic box half covered by a large bendy bridge & it's his favourite place to be!
Good wheels are a bit thin on the ground at the moment, the new design silent spinners don't work too well & the Karlie wooden wheels are almost impossible to get hold of.
The silent runner wheels are really good, mine have them & love them but they are big & take up a lot of cage space & many cages won't be tall enough to accommodate them easily so it depends on what cage you have.
There is a new wheel similar to the silent spinner which velma reviewed
here, I think Amazon sell something similar or maybe the same but I'm not sure.
I use the metal play pens for all my hybrids, as long as you don't put anything close to the edges they can't climb out & they're a good size for them, fold flat too.
If you go for the
stylish playpen idea you will need to block off some spaces at the bottom to make it safe for dwarf hams.