Not sure if this is what she may be seeing but I've notice that often when a software update is available (and you are promoted to apply via the console) if you don't apply it immediately, when you shut off the Blazer and lock it and leave, the radio will keep playing for 2-3 mins. I find this irritating as I keep thinking I didn't shut the vechicle off. Once the software updated is downloaded and applied this behavior goes away.