OP, I feel very sorry for you as this sounds very very hard.
But you really need to separate the issues.
You desperately need some therapy for your neediness for your truly awful mother.
You need this because your neediness has allowed her to stay in your home, behave so badly and emotionally abuse your poor 7 year old daughter.
Stop thinking of yourself for a minute and think of your confused daughter crying because her grandmother is an emotionally abudive liar, and mum continues to allow her to stay.
That woman should never have been in your home, given an opportunity to behave badly again and abuse hour child.
This is so awful.
Get some therapy for yourself because your neediness for this truly awful woman has allowed her to be around your children.
I wouldn't want someone so awful within a 100 miles of my children.
You know she is awful, she continues to be awful, you give repeated chances to be more awful, yet are surprised when she is awful......AGAIN🤷🏻♀️.
Stop it.
Accept the truth of who she is and stop wishing for what will never be.
And don't ever allow her to emotionally abuse your children again.
Mind yourself.
Why you are getting that water is beyond me.
Your husband should get it, or go without.
Rest up.