Too sick to ride?

Parent of the little girl that rides Romeo & Chewie called me today. We are all scheduled to attend a show this Saturday, with the little one showing Romeo in-hand. He calls to tell me she has a fever with a throat infection, and is on antibiotics "and other medication".

I immediately asked for how long on medicine? 10 days, starting today. I responded "She isn't showing. She's staying at home to get better. The risk of her getting hurt by a horse is too great, not to mention the risk of making some other little kid sick. I'll talk to you about a lesson when I get back after my week out of town."

Did I do the right thing? He wanted to call me back tomorrow "If she's feeling better enough to come tomorrow & help groom up horses and/or show Saturday." I think it's not worth the risk.