New snake owner with vomiting 4 month old

I bought Persephone 3 weeks ago at a pet store and it seemed like she was doing pretty well, she had no problem eating frozen pinkies and seems to be gaining confidence in her enclosure. But after feeding her on thursday evening, I woke up on sunday to find what I think is vomit. I have never owned a snake before and I would really appreciate some advice, my preferred vet clinic is closed on sunday and I don't know if how serious something like this is.