phoneUK50 wrote thank you for the suggestions and questions. I am connected via ethernet between PC to router and then from ethernet from router to AV600. I disabled my antivirus software already...

Hi there, Here is a beta utility for Mac 10.12 from TP-Link. http://static.tp-link.com/beta_PowerlineUtility.zip

What's the LED status on the two powerline adapters? You need to make sure all the lights are on. It doesn't matter that the network name of the wired connection is the name of your SSID, that...

Did she do Wi-Fi Clone? If no, then the default wifi network name of the powerline extender is something like TP-LINK_xxxx, not the same name as the router. So she can check if there is a TP-LINK...

You don't have to buy the same model, all the powerline units in TP-Link can work together. You can purchase a single unit(not a kit), like TL-PA4010 or TL-PA411.

If all the lights are off even the power light, then I think no other ways to try.