(((Rainbowzz)))

Vent away!!
I think you have every right to be upset. An adult, no matter what their age, should be respectful of children.

If your mother is a narcissist, there is no logic other than what they want. Don't even try to figure out her reasoning. And, don't try to waste your energy getting her to change.

IMHO, your anger is there for a reason, to protect your child. Listen to that anger, and do what you know is right.