The medicine they sell over the counter for wet tail is useless. It's actually worse than useless because it keeps people from taking their poor hamsters to the vet to get proper medication! It may actually cause them to be sicker as it is a derivative of tetracycline (in most cases), which shouldn't be used with hamsters, they are sensitive to it like guinea pigs are.
Baytril is a prescription antibiotic, and that's what your hamster needs. I wouldn't waste more money on that junk from the pet store. I'm amazed that she's lived this long!
We are as gods to the beasts of the fields. We order the time o' their birth and the time o' their death. Between times, we ha' a duty. - Terry Pratchett.
"Men have forgotten this truth", said the fox, "But you must not forget it. You become responsible, forever, for what you have tamed. - Antoine de Saint-Exupéry