Too feel sad for DS?

[Hamjamwich]

I've just asked my SIL and brother to meet up anytime over Xmas and new year. Any place of their choice, inexpensive pub meal or similar. SIL and BIL are off work for 2 weeks. We live 2 miles away. DS has said he misses family activities from lockdowns and asked if we could all meet up for a meal.
SIL reply was a blunt "no thanks"

Well she doesn't like you or you've upset her. You probably know which.

What's the rest of the story?

Shes allowed to not want to meet up with you all at the moment (or anytime) but i do feel there is going to be a slight backstory coming.

What has your brother said when you have explained why you wanted to do it?