I have a theory about fakie ponies that connects to Thelma:

Fakie Ponies irl are mlp knock offs. In the MLP universe, they are a strange race of mutant ponies. They have a Princess named Rinse and Spit, and she looks a lot like Thelma. I have also based Thelma's name on the Fakie ponies as well. So do you think she could be a Princess?

Fakie Empire