Sister sewn lips together because she say's it makes her sad?

i honestly cba to go into the story in detail but inshort, my sister aint quite right she has 2 imagenary people who are out to get her, she thinks that by cutting herself she will bleed them out she's done some bad things in the past....what ever a while ago she swen her fingers together. she has just come into my room with her note pad thing and wrote on it that she has sewn her lips together because she dosnt want to should because she say's it makes her sad, please any ideas of how to help would be greatly apreciated im worryed about her