I'm sorry for your loss, I've never experienced the loss of a parent yet but I'd imagine it would be freaking impossibly difficult.

Your co-workers need a swift kick, perhaps they were bitter/resentful of you in some aspect of your work?

And they're now sucking up to the boss and trying to earn brownie points in some sick way. I'm sorry for your boss and her husband though.

You are not being petty, you're experiencing a valid grief/grievance against their poor treatment of you and their lack of compassion. I'm sorry.