Does this Molly fish have a tumor?

This Dalmatian molly has grown exceeding large in size and she’s now at the point where she can no longer swim! She is just hanging at the bottom of the tank and only moves when jostled or scared. She has had no other symptoms at all except she has grown in size. Initially I thought she was pregnant as she did have 8 fry a few months prior. But it’s becoming more evident that she has some aquatic disease. My research has proven useless as I cannot figure out what is wrong with her, any suggestions??