I have 3 kids at home 24/7 that need regular attention, feeding, homework, etc. My productivity is down -- not because I am WFH, but because my entire family is as well. This is not a regular WFH situation and should not be analyzed as such.
I've also seen a couple of people without kids really struggling due to the lack of social interaction. For most this isn't an issue, or if it is, it's not a big deal, but for some, it's really hard to replace the in-office dynamic with video calls.
The current situation is a lot tougher, though, since a lot of the things she'd normally do with the kids during the day are denied right now: the zoo is closed, museums are closed, playgrounds and parks are closed, gymnasiums are closed, no play dates with friends, no visits from family, etc.
I think it's unfair to try to draw your conclusion from the present situation.