Turns out Lucy had Roseola, which I had never heard of before but apparently it is super common and every baby and toddler gets it. Humph, who knew. It starts out with a very high fever and no other symptoms, and days later the fever breaks, and then a rash appears. A rash that covers the body and looks just like measles, so it is a little concerning. She seems to be doing fine now, almost a week later.
I mentioned the illness to Aunt Jenny and she asked me if I was familiar with Roseola, and I said no. She shared a funny anecdote, in that apparently when she was adopted, her mother wanted to name her “Rosie” and her father put the kibosh on the name, because he said “Rosie Role” sounds too much like the disease Roseola! Pretty clever dad. Incidentally, 40+ years later, they did give the name Rosie to their dog!