You are trying to rationalize something that is not rational. I think the guy could take in the daughter but not the woman. Maybe you are right that he just wanted the best for the daughter and give her full family. Or maybe he forgave the woman because he loved her that much.And in fact, the story is summarized in the message. No extra details.
Therefore, the judgment is the same, not taking into account these missing details.
As it stands now, it looks like this:
The woman was married, something went wrong in the marriage, she left for another. She remarried and had a daughter. Then, completely spitting on the current family life, she takes it and runs away to the ex ... At the same time, without thinking about what her current husband will be like, nor about what example she will set for her daughter ... Well, apparently, this is also to blame "true love" and "high family values". Then, something went wrong again with her first husband, and she, with a new child and a grown daughter, after more than 5 years (!) Of absence, returns to her second husband ...
Attention questions!
1) But will it not happen that in a few more years she will run away somewhere again?
2) And when she left her second husband for her ex, what didn’t suit her in a man?
3) Will she look for a lover on the side for the same reason that she left her second husband?
3) So what kind of example does she set for her daughter?
With what we know, there can only be one answer. If I were in a similar situation and we either didn’t have a daughter, or she stayed with me, I wouldn’t let this woman even on the threshold.
Just because I don't want to waste my life and my feelings on a woman who doesn't care about anyone but his own convenience. For she returned to the second man, only because she most likely has nowhere else to go, and fathers usually love their daughters very much. And thanks to her daughter, a man would not drive her away. This is just a pragmatic calculation and the use of a man's feelings for his daughter for own purposes by a woman.
And there is no need to pity or sympathize with such women, otherwise they will never begin to appreciate the love of men.
"I don't want to waste my life and my feelings on a woman who doesn't care about anyone" - none wants but many will. Feelings aren't easy to control and some can't control them at all. And that is just the surface of it but i don't want to get philosophical, this is not a place for it.