How would you tell/advice a friend who has really bad body odor and makes really annoying habits?

she sits next to me, she doesn't put on deo and has really bad breath.sometimes when she talks to me I'll smell her body odor and bad breath with makes my wanna puke. And when she hears a joke, she'll laugh and hiss like snake (that's really loud and weird) OK that's about it how would tell or a advice her without hurting her.? I mean someday I just gotta let her know.