I am trying to not worry about it. It wasn't the response I was expecting, not sure what I expected, but that wasn't it.
It would have made me angry, also! It has nothing to do with the fact she was texting while driving. She knows not to do it, but you are the last person she wants to hear telling her what not to do. She's an adult! Even though she has your kids in the car, I can see how you come off sounding like her parent scolding his child, or a preacher shaming a sinner.
You had every right to feel like you did when you saw how she was driving. Just telling you why you got that kind of response from her.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!