You can add different treats to make it more interesting. Dari cobs, wheat sprays etc (jr farm and rosewood do some) go down well and they do enjoy picking bits off them (or stripping the things entirely). An idea that doesn’t take up extra room.
Also handmade treat balls that you can hang or put on floor - there’s lots of different kinds. You can make them out of cut up toilet roll tubes made into a sphere and stuff with tissue and her favourite foods.
DIY Treat Ball
It’s little things like this that they enjoy you don’t necessarily have to go and buy lots of new toys