Ok just checked your other post about the chewing! So she's in a hamster heaven at the mo, which is a good sized cage. It sounds like she is just a chewer. I wouldn't try meshing inside the cage - they can still chew mesh and just end up cutting their noses!
The perspex tanks I linked are a bit expensive if you can't afford another cage. I noticed others suggesting bin cages, which is a good idea. But to get a big enough one probably wouldn't work out any cheaper than getting a Zoozone 2 so I reckon that would be a good option - and look out for second hand ones (although you probably need one quickly!). Then you would need a piece of mesh which wouldn't cost much as just big enough for the lid - and some cable ties (about £1 for a pack).
Meanwhile I'd try a few things to try and break the habit. Scatter feeding has been mentioned. Sometimes it can be that something isn't right about the cage set up for them. You said she has plenty of substrate and a big wheel. All I can suggest is - check the wheel is working ok. And maybe try changing the set up slightly. If you have all the plastic shelves/house the cage comes with, try taking one or both of them out and putting a large house in on the floor of the cage on top of the substrate (eg an upturned shoe box with a hole cut in for the door would do) and a bendy bridge over the door as a kind of tunnel/access onto the roof - makes it dark inside and tempts them to nest inside. You cut the bottom out of the shoebox and use the lid as a lift off roof and cut a hole in the front for a door.
This will distract her and she may be so busy building a new nest and sorting herself out she might stop. Some hamsters don't like a lot of space over their heads either so a rat sputnik or tube tied to the roof can give some cover (ideally a rat sputnik could be next to a shelf for access). My old cage was the same height as the hamster heaven and the rat sputnik was good in it as it hangs so low they can climb in from the substrate level.
The only cost there would be the rat sputnik. This is how I had Charlie's old cage set up - it's exactly the same as the Hamster Heaven but without the tubes and smaller bar spacing.
The large house is on the right with the bendy bridge over the door. 10cm medium rat boredom breaker tube tied to the roof - it leads from the house roof to the sputnik (originally that was to stop him jumping out that side! But he loved that roof run tunnel). The sputnik fits in front of the wheel with a bit of space to spare between them. I had a vine log on the left so he could climb up to the other side of the sputnik, but a shelf does the same thing.
This evolved around what he seemed happy with. He seemed to like things over his head - the tube and sputnik gave that roof cover and his favourite place to sit was under the sputnik. The roof tube also seemed to make him feel safe higher up (ie overhead cover). And he liked the large house a lot and built a huge nest and moved his wee corner inside it so I then put his potty inside the house.
So a change of set up might help. The little plastic pod houses in the Hamster Heaven don't really allow for hoarding very well. This is basically what the hamster heaven would look like if you took all the plastic shelves and houses out and started with an empty cage.
The only other thing I can think of to try is a bit of training. I'm not sure where her cage is - is it in your bedroom? Anyway as soon as she starts chewing the bars, turn the lights out and leave the room. That way she won't get attention.