Well, i don't think they're portraying her mum that way because we don't know who is her mum and who's her aunt. Also, they were all brainwashed and so was Psyche, so I feel like I understand even if it doesn't excuse their behaviour.
You’ll be so surprised if you keep reading then everything makes sense like how the priest and Eros know about the body switching
Is that a spoiler? I'm only at chapter 204
Then haven’t you read it already? How the priest knows about body switching? It’s around chapter 202
Ok, but if I were Psyche's aunt, I too would be pissed off if my sister was chosen over me just because she smiled.
But for real, everyone is crazy in Psyche's family. Her dad, her aunt, her mom (yes her mom is weird too, no matter how much the author tries to portait her as the naive girl who melted Psyche's dad's heart).
Psyche please run away, for real T-T