I’m sorry, I’m with Lissa.
If she does get pregnant, and Mr Wonderful fucks off into the wide blue yonder, then she will raise the baby herself.
Not because it’s right, not because it’s easy, but because for someone with that level of self-esteem it is the only unconditional love on offer.
Lissa, don’t forget, babies love back, and right now that’s actually what this girl both needs and wants, love from a real human being.
Dickhead and a baby are not the ideal suppliers however.
Nothing, and I mean NOTHING is going to work until she has enough self-respect and self esteem to get out of the relationship and find someone better. Anything else is merely damage control. Nagging about how irresponsible she is, how she couldn’t raise a child, how she’s throwing her life away etc etc is not going to work. All it does is make her feel worse, make her need this jerk more.
Tell her how special she is, how beautiful, how good a friend. Tell her she deserves more, tell her it breaks your heart to think about her like this because you know she’s worth much more, tell her that any man in his right mind would be lucky to have her, and that this jerk is taking her for granted.
Tell her what she wants to hear, maybe she’ll believe you eventually.
If possible, try and get her some professional help- someone who can talk through all the reasons why she feels the way she does, so that she can see how stupid most of her thinking is.