Hi there!

When hamsters chew on their cage it is called bar biting. It is a behavior they aquire from being kept in captivity. The problem can be alleviated by spending lots of time with her (i.e. letting her out) and by having plenty of things for her to do in the cage (wheel, chew toys) and then rotating these toys so they don't become "boring."
The aquarium is a great idea as well. But be sure you still have toys for her or she will develop a different habit (ever see hamsters turn saumersauts in their cage?)
Good luck!