Some are saying Ella is Alice number 2. Let's talk about pyschology here , trauma and attachment patterns. Every person is different some are more vulnerable to challenging behaviour. Elsie is younger, older kids are more likely affected by divorce.
Alice parentifies Ella , this is a form of abuse. Ella has stronger attachments to her mother as Ioan spent long periods of working away and alice has obstructed contact.
Ella obviously has trauma from her mothers behaviour as she wouldn't behave the way she has.
Rightly or wrongly she feels betrayed by Ioan for leaving her with Alice, less money change, the living with Bianca now proposal has unsettled her attachment with Ioan.
This is traumatised kid who's being solely parented by an abusive mother. I see Ella as having complex PTSD. Expecting Ella to jump with glee at the thought of moving in with Ioan & B is fair fetched. She probably sees Ioan as the more stable one so feels more betrayed by him as she thinks it's him setting Alice off.
Alice has conditioned Ella, the trauma will take a long time to undo. Alice parents Elsie in a different way , all her expectations are on Ella.
She's a teenage girl going through hormonal storms , friendship issues then deep trauma on top.
I hope she has a trusted third party to confide in.
She loves her mother deeply even though Alice doesn't deserve it.