Her favorite subject is math because she is good at it.
That's good to hear. Do you feel proud of her?
I feel so proud of her.
It is great that you feel proud of how well she is doing. It will help her succeed in the future to know that she has your support.
No, I wish she was better at cook.
Is this person that we are talking about your child or your partner? Because as you have said you are already proud of her, but you still expect her to be a better cook. I hope you don't get disappointed that she's not good with something else as she may be preoccupied with being good at math and it will seem very needy if you still continue pressuring her with other things.