My MIL was amazing - she was everything a MIL should be. I was made to feel part of the family, and she was always supportive of me - on occasion she told dh off when she thought he had been thoughtless or had done something wrong.
She was great with the dses - loved their company, enjoyed spending time with them and, although she didn't live close enough to have them regularly, she did have them all to stay with her, in turn, so they each got some 1-2-1 Grandma time. She was even able to get ds1 to practise his trumpet - something I utterly failed to do - and he wouldn't have got distinction at grade 1 without her.
She was lovely to spend time with - I always looked forward to her visits and knew that we'd have a great time - and I never once felt criticised by her - indeed, we had a running joke that I would tell her I had spent ages cleaning the house before she arrived, so she wouldn't realise I was neglecting her baby, and take him back - and her reply would be that I had signed on the dotted line and he was mine now, no returns or refunds!!
Sad to say, but I actually had a better relationship with her than with my own mum. I never felt I was a priority with mum, even when I was being bullied at school, to the point of feeling suicidal - and she has always been closer to my sister who is far more the golden child than me. I get on OK with mum now, largely due to the fact that we live several hundred miles apart, and rarely see each other. She thinks it is great that she is friends with her two dds - I have not disabused her of this notion.
MIL died a few years back, of lung cancer, and I still miss her terribly.