How do you deal with a family member who isn't able to tell the difference between something serious and a joke?

And who relies on the cues of other people to decide how they’re “supposed” to be reacting to things?

I have a family member with 4 kids who is just like that. She’s on Facebook. As a result she is stressing really bad over this C19 thing. Far worse than she needs to, and I really worry about the kids.

When people post that they’re having nightmares over it I wince. That’s her cue.

Most people are doing all right, but all the games to “break the monotony” is affecting her. She thinks she HAS to feel like she has cabin fever.

The jokes about “teachers” drinking on the job is another cue that she should stress out, because she can’t see it for the joke that it is.

I honestly don’t think this is much different from summer break, except that there is no public pool to go to. Other than that, the kids have always stayed in their yard. They have never been allowed to explore the neighborhood. Other kids never come over to play.

She hasn’t said anything to me, but she doesn’t need to.
How can I handle this, reassure her that it is not a requirement that she has to be stressed out?