ROOMATE KEEPS FARTING?

so we live in a triple dorm room...i mean the room is pretty small and one of my roommates keeps farting...A LOT...and i don't know how to tell her nicely she is sensitive and i dont want her getting hurt when i tell her...but i need to do it soon because it always smells like **** in our room....and the worst part is that she asks us why the room smells..UGH HELPPPPPP!!!!!!