Earlier quoted context omitted.
This seems to be one of the real costs of upgrading to the latest version of Windows. In this case your mom has to pay the bills, but in general I'm curious how long will it take for ISPs to launch a solid campaign against Microsoft, like they did with Netflix.
How is this a real cost, is there an estimate of how many bytes are sent and received and at what interval? If it was anywhere in the thousands of megabytes regularly, maybe that's the real cost but that's just an assumption.
Microsoft, please get your stuff together. Hire some privacy aware people.