Well, she is your mother. Mothers as a general rule don't like to hear one word from daughters that they may have some insight, and no such good deed goes unpunished. Naturally she feels the need to defend her position.
You did ask for it...now it's coming your way!
In these situations it might be best to simply agree with her and lend your ear, mmm hmmm, until your ear gets a little tired, and then, talk later mom...got some things I have to get done right now....
Now I know you don't want to appear righteous, so...texting these little insights might be thoughts you might want to keep to yourself....just a thought.