You do realize TOR is going to be unsafe for the average person and their every day browsing, right? Your traffic is going to be visible to any person running an exit node, so if you send any personal information or login credentials over a non-https connection, the person on the other end can read your information.

As someone else mentioned, if your mom is a journalist or political activist, and needs to access information anonymously, while at the same time is careful enough not to release any information over TOR that could be used to identify herself, than it might be in her advantage. If you're setting her up on TOR so she can browse her favorite social networks, cooking blogs, and e-mail, then she's most likely going to be less secure, entrusting personal information to strangers instead of her ISP, and waiting on the slow load times of the TOR network.

TOR isn't some magic bullet that makes browsing safe and anonymous. In short, I'd recommend your mom doesn't use TOR. Based on her profile, she's going to make the mistake of sending unencrypted personal information, and when that happens, I think she's better off trusting her ISP over a stranger with that data.