We perfectly understand your point, MyBrainHurts, and we don't agree with your solution. We ARE telling her how not to end up with a dirt bag.
The reason why she always ends up with men who treat her like crap is that she feels like crap inside. The only way not to end up with such a guy is to change her thoughts about herself and about life. As long as she doesn't change how she feels inside she will keep on attracting crappy guys, no matter how many men she dates, no matter how patient she is.
What makes her unhappy is not the guy at all, it's herself. So giving her advice on how to get a better guy in order to be happy misses the point. No man in the world, not even the sweetest of all, will ever be able to make her happy, if she's not first happy on her own.
And to be happy on her own, independently from any guy, she needs to understand that what determines her happiness is her thoughts. It's not something that happens to her, it's a choice. She has full control over her mind. No other person, situation or thing has any influence over her mind, and therefore over her happiness. It's not the other person, situation, etc that makes her unhappy, it's her own thoughts about it. She can choose to be happy, to think happy thoughts and to love herself. And then she'll be happy.
Rio, sorry for talking about you in the third person. I wish you all the best