My own MIL behaves like this. After so many Christmas cancellations, last minute unavailability when everyone has booked annual leave & packed to visit her, missed birthdays etc I’ve given up. She talks absolute trash to people about how I’ve come between her & the kids but I know, that she knows, this isn’t true & the crap she comes out with is motivated by shame that she’s an absent grandparent to her DS’s children. I used to lie to the kids and say ‘poor granny can’t make it, her car won’t start / bad tummy’ but now I don’t tell them if she’s planning to visit so it’s either a nice surprise if she arrives (rarely) and no harm done if she doesn’t.
DH just accepts this as ‘normal’.
i’ve stopped inviting her now & when she calls & tells me she misses the children I just make soothing noises and say ‘you must let me know your availability, we’ll definitely put something in the diary’ rather than trying to ‘fix’ the issue, and she never confirms a date.
I don’t think she’s a horrible woman. I’m sure she loves them in her own way and I think their relationship will improve when the children are adults, though sadly she will be quite old then. I think she enjoys the idea of children a lot more than the reality & feels ashamed of this but she shouldn’t, the only person judging her for that is herself. What she needs to stop doing though is blaming everyone else (DH’s dad has taken the brunt of the blame for no reason that makes sense, followed by me, DH, DHs ex girlfriend the kids mum, the kids other grandmother, the dog, probably the local shopkeeper and maybe Tony Blair, you name it anyone but her own choice). Jokes aside she can get really nasty about it & I do wonder sometimes is she actually mental to keep persuading herself that we’re all working against her, when it’s her choice?!