Yes, your daughter is probably too young to really understand. Your wife is trying to buy her affection and upset you. Narcissists are all about power and control. I had to learn to understand that about my sister.
It’s good that you have therapy tomorrow. I hope this therapist can give you tools you can use. It’s especially hard when the toxic involves children. Do your best to stay calm. Do a lot of humming as I read that reduces stress.