Although the rash doesn't sound quite the same we had this the other day. DS was diagnosed with tonsillitis. given amoxycillin. After 4 days he was fine, then started really high temps again. We were worried the ABs were wrong so we took him to the hospital who stopped the ABs and said let it run its course. 2 days later he had an awful blotchy rash all over his body. Took him back to the dr who said he was misdiagnosed for the tonsillitis and it was probably glandular fever as a lot of the symptoms are the same although it isn't common in really young kids. Supposedly the rash is a reaction to the ABs because of the glandular fever. If you google it you can see what I mean. I was wondering if the same happened to you because you mention the recent illness and that you have just finished the ABs for her.