As it says when you unlock her, she is not canon, what happens around her is not real, she should not be considered as apart of Harem Hotel's story and what happens in Violet's story does not represent what other character's may do or act like.
Violet is in her own pocket universe and should be treated as a Dreamscape. With the code spinningtv you'll be able to unlock her and she will act like a character in the Hotel with a room, story and stats that Mr.Dube (The patron) directs. Violet isn't necessarily a new girl, nor is she a side character. But she is an unlockable character that plays like a main girl.
An example of what I mean is, eventually Jin will be a side character you can buy eventually. Once you do, she'll be both in Violet's room and wherever she'll be when she joins as a side character. Technically this means there's two Jins if you use Violet's code.