Friend casting doubt on my relationship to make herself feel better after a nasty breakup--how to handle?

I have a friend, L, living abroad. Few months ago, I was visiting her and met a guy, B. We spoke frequently over email, and on my return saw a lot of each other. We both see the potential for love and future, especially since I happen to be studying abroad not far from him next year. The friend I have to thank for my meeting him just broke up with her boyfriend as I was on my flight back. I've spent a lot of time consoling her; I'm her friend and I'm glad to help, but her ways of coping are hurtful. B was a flirt and a playboy. He told me this straight out and that he has no interest in doing it anymore because he respects me. I trust him. L seems to delight in bringing it up, disguised as concern that I'll be hurt, offering to keep her eye on him while I'm at home. I find it hurtful that she brings it up, as if making sure I know that while her love life isn't great, mine is worse. I'm getting sick of talking to her b/c she has nothing to say, and I was wondering if anyone had advice?Friend casting doubt on my relationship to make herself feel better after a nasty breakup--how to handle?
She obviously doesn't sound like a true friend. He seems unsure of himself as well. Get on with your life, meet new friends and Im sure the right guy will come a long for you. You don't need friends like that in your life.