Right, I'm not sure whether I'm being unfair on her, but recently I've started to be a bit suspicious of her and how she treats her grandchildren. The crux of it is something that has happened recently.
MIL has always looked after her 2 oldest GCs (I'll call them A & B), who are now both at school - she has them after school until their mum (her DD) picks them up. This DD is MIL's favourite of her children, and that has always been obvious. DH says the rest of the siblings have been aware of the favouritism basically since they were all children.
One of DH's sisters used to live quite far away, but recently moved with her DH and DD to be closer to PILs. Her DD (I'll call her C) was very settled with a lovely childminder, who she adored, but is now being minded by MIL every day.
It has been obvious from the start that MIL was much less fond of C than she was of her other GCs. She's always complaining about C's behaviour (C is only 3, and is a lovely, bubbly, polite child). She has been known to complain in front of C, or while C is listening. Any time anything happens between C and A or B, C gets the blame (although the other 2 are a few years older, and much less well behaved in general - I've seen them pick on C, push her, and refuse to share with her). There have been times that the 3 of them are playing, and C does something rough, copying the other 2, and C is hauled out and shouted at while A & B watch on and laugh.
After C moved house, she became very unsettled and her behaviour deteriorated a little bit - nothing serious, just a bit more tantrum-y, pushing the others a bit, that sort of thing. From my pov, it seems that it's just her reaction to having moved house and being taken away from her childminder. MIL announced that C needed "a good smack" and said that that's what she planned to do if there were any more tantrums. C's mum said that she didn't want MIL to smack C, and suggested some alternative strategies that have worked for her in the past.
Of course, C threw another tantrum, and MIL smacked her. She then started boasting to other people that she had done this (my mum has a friend who knows MIL from an organisation they both go to, who told mum this), and that her DD (C's mum) could either put up with it or find another childminder; she didn't care what happened as she was sick of C's behaviour and of her being such a spoiled brat. I thought it was awful that she seemed to be prepared to go against her daughter's wishes and not even try the other strategies suggested, and that she is so quick to bad-mouth her granddaughter, and has such clear favourites.
I've largely stayed out of all this as I don't think it's my business, but it makes me nervous about having MIL look after my DCs. She doesn't mind them regularly, but from time to time if I have something on, she might take them for the day, or after school for the afternoon. I can't stand the thought of them being treated differently to the other GC, or of MIL deciding they "needed a smack" for something, or of MIL going round telling her friends that my children are nasty, spoilt or unpleasant.
Am I being unfair on her? DH thinks there's no problem with her looking after them, as it's only for short times, but I'm uneasy about it.