How about this? It may not completely cover the wire shelf, but if there's a gap at the back you could put a bit of cardboard there. A smaller bit of cardboard is easier to keep replacing. Or two overlapping mats? These can be safely chewed and would take some destroying I think so she may not bother.
https://www.amazon.com/Aoile-Breaker...y&sr=8-1-fkmr0