What is on Prudence's Eye?

Yesterday afternoon, I noticed something on Prudence's right eye. It was a pink "growth" (for lack of a better word). My first thought was pea eye, but after actually looking at it, I realized that, no, it is not pea eye.

Several hours after I took that picture, I checked on her again. The "growth" was bigger. This morning, it looks worse. She as a vet appointment in two hours. I hope this is nothing serious.