[mangoandmimi]

Steel angles is the best option of those three - re sealing probably won’t be any good as she sounds persistent. And plastic just isn’t safe since you know she chews.
When I made my cage I used pine quadrant moulding (basically quarter circle rods) as it’s pretty hard to get a good grip on it if you buy a smaller diameter one. Just glued it into place with Ponal glue and it didn’t budge - not that my hamster was very interested in it.