Hi Reverse and welcome,
I too have had to distance myself from the chaos in my alcoholic family of origin in order to become a healthier, happier person.
For me, I found it easier to establish physical and intellectual distance, it took a while for my emotions to catch up and I am still working on it, so go easy on yourself.
One of the things that I have had to learn to let go of was any expectations I had of how my alcoholic brother and codependent mother SHOULD behave. I have had to learn that I cannot control their actions and to let them go and concentrate on myself.
Can you see how your expectations that your mother should learn to drive are causing you pain?
Think, what would you like - you would like your mother to visit your children. Let her make her own decisions of how she gets to you - she is an adult, she can choose to get the bus, if she only gets an hour with you before having to go home, that too is her choice. If a relative decides to drive her, that is the relative's choice, let it go. When she gets to you, refuse to discuss how she arrived, after all she has travelled to see her grandchildren not complain about how she got there. If she doesn't make it to you then that too is her choice and her loss. Just keep concentrating on you, your hubbie and your kids.
A good book that helped me look at how I was unhealthily enmeshed with my alcoholic family was Codependent No More by Melody Beattie.
Glad you've joined us, IWTHxxx