She had her screen lock and a message on Chrome saying that she needed to "Call Microsoft" and she wasn't able to close the window, etc. So she called and "John Henderson" was able to talk her into installing LogMeIn. He then started about charging her $149 and she came to her senses and called me.
I'm 99% sure that she was served some Javascript via an ad network.
I installed uBlock Origin on both of her browsers. I tried changing her DNS to Adguard but it turns out that Comcast hasn't let people change DNS on their routers for many years. Even if you change it on your personal device, they'll force DNS on you.
I have been debating putting ad-blocking on their computer because I've worried about something like this happening. I'd also worried about some site not functioning properly because of ads being blocked. But we'll deal with that if and when.
Sorry but not sorry to sites that are doing 3rd party ad networks that they don't audit.