You shouldn't worry yet.
Every ball python has it's own schedule. Some poop weekly other monthly (mine poops monthly for example) and some of them take even more time.
I'd wait. If you're really worried, take a look at the far back of her tail. Is there a part that looks swollen? If yes, you could try to give her a bath in luke warm water. Many ball python relieve themselves then.

P.S. Are you sure a hopper is the right size for her? It sound a little small.