I don't blame her, if you have literally no experience or perspective on a parent being bad it's probably not something you can imagine without more life experience.
It was inevitable but oof it hurts to see it finally happen. Hopefully she doesn't overcorrect in trying to be sympathetic and understanding after this...
And this is exactly why I said I liked the mom in the last chapter. She could tell just from how she knew her daughter was that she didn't understand a single thing about her friend. But she had no plans to clear up anything and knew eventually it would hit her with a dose of reality. I hope we get her mom's POV in the next few chapters.