I apologize for poor quality pictures. Rosca is a little wily and so it was hard for me to get a better look myself. For the .2sec I could touch her head, it felt rough.
This is my first time handling her since she last ate; I watched her take the rat down and made sure it was a downhill battle before I tended to my other snake. It wasn't like she was attacked. But it wasn't there (that I noticed) prior, though it could have been, and it doesn't really look like something crusted on... help?