That's a good guess... cuz I was dang confused on why she was the one blamed... like... they were going to the grandfather's birthday right? And she wasn't the only survivor... and why wouldn't the father be together with them? So I don't get why he hates and blames her...
My only doubt is that they were a happy family before that... so maybe that chock awoke her powers and she went out of control?
I feel like they were okay because the mother was glue. If she wasn't there (like if she died giving birth to the brother) I doubt it would have been a good family situation. Also the shock could have awoken her since if she had her powers she could have saved them by accident. Elle is too powerful and she formed a contract while she was still pregnant with him so he isn't a good baseline.
Ah, I think her mana caused SNAFUs often as a kid so they called her cursed. They must have assumed the carriage accident was the same. Still BS though. Also I'm starting to think Elle rewound time somehow