I need to know if I'm overreacting

I'll try to keep this brief. My MIL lives across the yard. We're always going over there to hang out. The weekend of March 21st she spent all day going out to a large city (with a confirmed covid-19 case) shopping. Last weekend she spent all weekend at my SIL's house (she's a nurse at a hospital and her husband is an EMT) watching their kids. Big risks IMO for a woman with numerous health conditions. I told my husband that I don't want my kids at her house right now with her going out all the time and that it would be great if he could stay at home as well to help make sure the kids don't get sick. Now that I'm starting to work from home and I need absolute quiet, he'll have to watch the kids for several hours a day by himself and I know he'll end up taking them over there because he's too lazy to watch them alone. Am I overreacting? Should I just let the kids go over there or stand my ground?