Parents with kids on oxygen or with visible medical needs/devices... How the heck are we dealing with the rude and judgemental parents who treat our children like they're lepers?

My five year old is recovering from an asthma exacerbation and is on oxygen right now. We're hoping she'll be off it in the next few weeks.

It's hard because she still has coughing fits and post-pandemic, people are less than kind about it. On the last day of school, a parent volunteer told me that I should have kept her at home if she was sick. I told her she's not sick. The volunteer was really pushy about it and said that my daughter is obviously sick because she is coughing and on oxygen. She said I should have kept her home so other kids didn't get sick right before Christmas. I told the volunteer thank you, we do keep her home when she's sick, but she's not sick. She has asthma and asthma is not contagious. Her doctor gave her the all clear to go to school.

Today we were shopping because that's what my daughter wanted to do. My daughter had a coughing fit so we sat down on a nearby bench so I could give her all her inhalers and whatnot. A little boy (maybe 3 or 4 years old) was like 15 feet away reading with his mom when the mom said very loudly, "You'd think people would be considerate and not bring their sick children into a children's store infecting everyone. Let's go before we both get sick."

I was too shocked to say anything but I wish I had. This is happening more and more for us but I don't know what to do other than ignore it. I'm not confrontational and don't want to start stuff but I don't want to teach my daughter that letting others be judgemental and rude like this is ok.

If you're the parent of a child with a medical device or very visible medical needs, how do you deal with people like the parent volunteer and mom in the toy store?