I always thought the core of "Karen" was more the entitlement mentality they embody than the acts they do. In this case, Yuuna's mom clearly believes she is entitled to the right to run everyone's life as she desires, which is why she replaces Ponko without even the barest consideration of anyone else's feelings and treats her child like an object. To her, Yuuna is just an item of personal property to use as she sees fit. If Yuuna does not perform as desired, she will be beaten (mentally and/or physically) until she does. The same goes of anyone who has the misfortune to encounter her. Her existence entitles her to run the entire world as she sees fit, and anyone who does not perform as desired is clearly wrong and must be punished - which of course she is entitled to do.