No, you want to use the owner of the entity. $entity->getOwner()
Oi! of course! a little tired when i was working on this...thanks Cash.
Just a side note for anyone interested in what i've been doing with this-I did a little change with what i'm mentioning above, I replaced $entity->getURL(), with $_SERVER['HTTP_REFERER'] to direct the user to the page of the content being referenced in the notification...so if it was a post let's say on the user's profile river(using river_comments) then the link will direct them to their profile, if posted on an image(using tidypics) then it will direct them to the image location.
Hope this helps anyone in need. : )