Saw your other post about the wheel grinding
Standing it on a piece of wood sounds like a good idea. You could even attach the base to the piece of wood with little u nails. If you were looking for another wheel, as mentioned, the Karlie wood wheels are quite stable (but also work better on the floor of the cage - you can fit about an inch of substrate under it and then slope the substrate away uphill so it's deeper elsewhere).
Zooplus don't seem to sell it any more, but they do sell the cork lined one
Which is nice for their feet, but you would need to plastikote the wheel and the cork in case she pees in it, so it doesn't get stinky. Our hammy very rarely pee'd in his wheel, but some do. It might be an option if she doesn't tend to pee in her wheel.
They are also silent wheels
It's a good price - the cork wheels are quite expensive on Amazon. Although there would probably be postage costs on top.
Trixie Wooden Exercise Wheel | Free P&P on orders £29+ at zooplus!