I would place my own mother is in the crap category rather than the toxic one.
To those with toxic mothers I would suggest that you read "Toxic Parents" written by Susan Forward. Whilst not a panacea at all it may help you find another way forward.
I smile wryly to myself when I see "Grandparents Day" or "Grandparents of the Year" contests. Would not enter my parents into either.
I've noticed how much more Mum in particular (and my Dad come to think of it) have changed since becoming a parent myself. There were subtle changes before then too; when I met my future husband I think their noses were somewhat put out of joint. Infact when my DH was on his stag weekend and I was at home with my parents I heard my Mum talking about my future DH to Dad in the kitchen. I was so upset at what I overheard I almost walked out there and then. My Mum was afraid that I'd end up getting divorced .
My Mother's priorities these days are cleaning my brother's house (he is both single and childfree) at least once a week, shopping and holidays. In general both Mum and Dad do far more for my younger (by two years) brother and generally try to keep him happy. They've picked him up from the airport in the middle of the night, even when DH and I were a couple we were never collected from the airport (well I never asked because I knew the answer in advance). Its her life after all but we as a Meerkat family unit do not get a look in. I cannot honestly recall when she last saw my son (apart from Christmas that is and we went to their house which is 20 minutes away).
She's never been to any school event like the Christmas play (always cites I'm too busy as a reason) so I no longer ask.
If we go out to the cinema in the evening I use Sitters. Got fed up with being constantly told "no".
We are going on holiday at the end of next week and I asked her yesterday if she is going to see DS this week. She replied that she'll see what things are like around there. She'll probably get some milk in for me.
My parents are both fit and healthy currently. My Dad no longer works and my Mum raised us both at home.
I think there are depressive and obsessive compulsive (this arises to me from the constant cleaning) elements behind her actions, I think I'm going to have to have a chat with my Dad about her behaviours - again.
My Mum only has one female friend whom she rarely sees, the rest of her life is taken up with the above. She is a very solitary animal my Mother. I feel both anger at her disinterest along with a degree of pity. She is an abject example in how not to be a grandparent, well they both are.