She had long noticed something was wrong with her son, but she couldn't find the reason behind it.
If she was a normal mother and her son was a normal young man, she could have passed it off as a phase of young age. But with Kruel, that wasn't the case.
He was no young man, and nothing he did was without any reason that she was sure of.
Her only concern was that whatever the reason was, she hoped it was for their good and best, and he didn't do something that could harm himself.
Plus, the timing was also not in their favour. When the North was ready to face them off, his behaviour like this was not in the favour of witches, particularly his. He had to decide, yet he behaved nonchalantly throughout the situation.
But it's Okay; her father has made the decision. He was ready, and so was she. It was time to take long-awaited revenge. The final blow, after which she will be able to get what she wants.