You don't really get to choose what your child will be like. They're their own person and no matter how well you raise them, they could still turn out to be terrible people. That being said, they most awful thing about the queen is that she didn't even try. She decided her child was a lost cause from the beginning and didn't try to do anything.
Worse, considering how she mentions that it's odd how much love and trust is shared between Pryde and Stayle, I think she must have had some insight into how Pryde was treating others and did nothing. What's the point of being able to see the future if she's not going to do anything to make things better?
Also, why did she declare Pryde her heir if she had doubts? If the queen changes her mind, this would have been a huge blow to Pryde both politically and emotionally.
The most annoying thing of all is that I can tell the queen is being presented as one of the good guys by the author. She's probably not going to face consequences for what she's done. The dad might have more sense that her, but even he doesn't do anything about it. At most Pryde will call her out and then forgive her. She's a terrible mother. She basically showered one daughter with love and treated the other like she didn't exist.