You do get stories on mothers hating on their daughters. The Karen in this case may envy her daughter and wishes she could return to her youth.I don't know the full story either. To me it sounds like a mother who is maybe even jealous of her daughter. Maybe the mom is single and jealous of her daughters relationship to the point she'd try to sabotage it. Crazy people.
If the Karen has to serve time, who would be responsible for the daughter's care? If she is a single mother, the consequences could be dire. And yet it did not enter her mind.