I'm going to call my mother out on a major lie she told me my entire life
Why do you want to call her out?
I've realized that I can't trust her anymore.
Well, if this lie really is that bad, you should call her out on it. Parents and children should have trust with each other.
I often need to confirm that she isn't lying to me at times because I can't even trust my own mother.
If she did lie to you, I would say to call her out nicely. You can call people on their lies in a respectful way, too.