Sorry to hear about your rattie girl. :(I hate losing pets. It sounds like you did all you co uld for her im sorry you have to see her go though. I had a female rat named Cheza (dumbo rat) and she lived for quite a long time before developing tumors/cancer that couldnt be removed either. Females are very susceptible to tumors and cancer. My males Roley and Patches were awesome too, but Cheza was my favorite. They were all snuggle bugs.
Healing thoughts to you and your lovely rattie.
"People will forget what you said and they will forget what you did, but they will never forget how you made them feel."