Snarf,
First I would like to congratulate you on your posting.
My mother was a sadist (and a Regular Pioneer). She hated me from the moment I grew up and I knew it. For over 30 years nothing I have done for her has been good enough.
I dont have kids so feel a little guilty offering advice. But here goes. Try and spend more time with her. Even if it means slightly less fancy stuff (I am assuming you do not live in poverty). What does she want to do. Give her some control in her life. Let her choose the next family holiday. Let her hire a movie or decided what to do when the family socialise together.
With you working 5 whole days and your other half working 7 she may feel she needs more of you.
I do hope I have not been too judgemental. Send me a private message if you want to shout at me!
Love you lots,
mtsgrad