<human>: Can you give me a shortened version of the text?

So I have a friend who's not a redditor, but she needs help in this situation and I'd like to get some feedback from you guys to give her suggestions, as she came to me for advice.

My friend, let's call her Amy, recently got engaged to a guy [21M] who lives five hours away, let's call him Dave. I met Dave in college, and we had a strictly-sexual thing for a while, but it fizzled out when I caught feelings (I'm way past over it, this was in 2011 and I'm now engaged to the love of my life). I introduced Dave to Amy, and they hit it off right away. I was so happy for them when they got engaged in March! He's coming down next weekend, and Amy wants to go out with him without her roommate, Shannon (name changed). The only problem is, Shannon gets depressed and risks harming herself if Amy does anything with literally ANYONE without her. I know roommates are supposed to support each other and whatnot, but this is a little extreme. Shannon probably needs professional help (I've seen the scars on her wrists...they're not pretty), but she will not accept it. Shannon is single, and Amy said she'll just have to wait "until she gets other friends or a man comes along."

What advice can I give Amy to help her relationship with Shannon, allowing her to go out with her other friends/fiance without worry again?
<bot>: Friend is too worried about her roommate being depressed and self-harming whenever she hangs out with anyone alone, not redditor, and came to me for advice. Wat do?