MC seems like such a smart and independent lady (and lord knows she's got the money), I'm surprised she'd keep having kids with a cheater. Or stay. Pavlos doesn't seem worth it, IMO, and both her sisters have divorced their society spouses -- but of course maybe seeing that trauma close up is why she's stayed.
It is impossible to judge from the outside looking in what is worth it and what is not worth it. I see people do this all the time: "Why does she do that?" "What does he make that choice?" It's none of our business, but besides that, it is impossible to have any kind of objective understanding of another person's life choices. You may think something seems logical, but from MC's perspective, it looks entirely different, and she's making choices based on her own will, her own wishes, her own comfort, etc. What works for her does not necessarily work for you or for me, or her sisters or anyone else.