What should I do? So upset

My cousin is getting her c section done on Friday evening but she’s house sitting until then and apparently she needs a couple days to clean up the mess they made so she wanted me to watch her kids early and while she’s recovering from her c section. When she dropped them off she said they have Benadryl in the bag for their allergies, but I’m 99% sure she just gave me two kids with the flu. They’ve had fevers, horrible coughs, been throwing up, and just acting super sick. I’m 20 weeks pregnant and my OB hasn’t given me my flu shot yet so I’m terrified of getting sick while watching them. I’m so upset that she didn’t even mention it so I could have been more careful. Should I say something to her? I have no help with them so if I do need to go to the doctor I’m stuck at home for at least the next week. She does have help from her boyfriend but he’s lazy so she doesn’t want to put it on him, am I a jerk for wanting them to go home early, like a couple days after her c section? I’m not being paid or anything and I watch her kids A LOT.