I thought it would take a month or so, but it took less than a week for my daughter to break up with her boyfriend. She said she didn't want to, but felt like she had to. Translation - she loves him, but loves herself more. I'm sad for her and happy for her at the same time. It's hard to let go of a relationship that's lasted 18 months. It takes a lot of strength to say "this isn't going to work out for me". Especially when you still have feelings for the other person.
He still needs to be taken care of and she is too young to take care of anyone other than herself. She's also secure enough to know that she will be ok without a relationship. I think that's what hangs up a lot of women - men too. Being alone is too scary to contemplate, so they hang on even when it's time to let go.
She'll has a good support net, so I don't worry that she'll be ok, and now my waiting is over.