DM means well and does care, but can be a tricky character. With the exception of one Christmas she's always had Xmas Day with us. Think DH copes with it by drinking a glass of wine while he keeps out of the way cooking lunch, then by the time he's had another glass over lunch he lets things ride over him. She has no other family and two main friends will be away, so no one else to go to.
SIL has invited us for Xmas Day. DH said no immediately as DM will be on her own. SIL turned round and invited DM.
I'm 99% sure DM won't want to go to my SIL's (on DH's side, doesn't know them) and even if she does not sure I don't trust her to pick an argument.
Trying to be fair to DH here as I'm sure he'd like to spend the day with his family, but know my DM will be down if she's on her own all day. WWUD?