Whats wrong with my Rattie?? :(?

I noticed last night that my rat was making funny noises and i thought they might be hiccups because she had them before. But today she is making the same noises and they sound like popping and squeaking kind of. i don't know what it is? I Got my rat from school and i think she has that Mycoplasmosis but she isn't losing weight or anything just sneezing.My mom won't bring her to the vet. I even have the money and i ask her a lot to make me an appointment and bring me there. She said "Well do you have the money?" and i said "yes" and then she said "she probably has an upset Tummy or something" and then she just walked away. I don't know its like she thinks that my rats are just not very important or something. She brought her stupid rat to the vet every 4 months when she had it.I don't know But what is wrong with my Rattie??