Since I had kids 10 years ago, my mum has always provided 2 days childcare a week, when she worked and now she has retired. Ive always been careful to check with her, that its not too much. But both her and my dad insist its 'the highlight of their week'
My mum injured her back 3 years ago and was in constant pain with restricted mobility until she had an operation 6 months ago. She became really grumpy, shouty and aggressive over this time. She was pretty horrid and difficult to be around. We made allowances because of the pain. Childcare arrangement continued as my dad had retired by this point. Sometimes dd spent extra days in nursery so they didn't have to have her
Since the op she is pain free and there was an instant change in her mood. She seemed back to her old self.
Except now she has reverted to being argumentative/unpleasant/shouty. Shes just totally unreasonable. She argues with my 4 year old as if she is an adult. Today whilst I was at work, she stormed off home after dd refused to accept her 'help' with her drawing 
My dads at a bit of a loss and thinks shes having some kind of breakdown. I think she's unhappy since my dad retired. I dont think she likes him. Most of her anger is directed at him, but it spills over onto us also. Shes impatient and always seems to be trying to get away from us all
Me and my dad have both tried talking to her. She just shouts about how its our fault. I phoned her gp at one point. It made her very angry.
I don't know what to do