This is really positive news. I wish you all the success and positive state of mind in the world. You mention that she probably expected you to be….
My thinking is to try and avoid negative thoughts. Maybe she does or maybe she doesn’t. Definitely try not to rub her nose in your liberation or success if you can see her pissed off.
What is a fact is that she is the mother of your children and a pissed off mum is no good to anyone.
You want them to be happy, that means playing the game so that you can be a better person than the one who is being negative if indeed they are.
If you can look after yourself you can look after your family so conflict avoidance needs to be at the forefront if conflict exists.
Best of luck