How to confront my mom about this issue i have with her?

Yes I agree, you should confront her in polite manner and never be rude to your mum even after she did what she did but just try to make her be aware of what she had done to the family adn your dad. try using wisdom and becarefull on choosing your words. try writing them on paper or type them up on the pc then read it again and check for any corrections then go and talk to your mum politly and inform her about what she did was wrong