Hello,
Do you have a photo? How old is she?
Hair loss can be due to many things, if the skin is inflammed and sore then it will need vet atttention. Usually ivermectin (spot on) for small animals is the first port of call for skin/hair issues.
However, other things like cushings can happen , more in older hammies.
I don't know how old you are, but if your parents let you have the responsibility of having a pet, then they should also ensure all its needs can be met, which included providing vet care if needed. Sometimes, we have to be the more mature ones and explain to our parents that just because they are small, they still require the correct care
Some members start doing extra chores to save for a vet fund