She's ostensibly a senator for New Brunswick but Carolyn Stewart-Olsen been a denizen of Ottawa since the mid-80s.
According to her Wiki entry, Stewart-Olsen served as head nurse of ambulatory care at Ottawa's Grace Hospital in 1986 before moving on to work as nursing manager at Carleton Place hospital. She hooked up with the Reform Party in 1993 when it became established in Ottawa. She worked for Preston Manning and Deborah Grey before becoming Harper's press secretary in 2002 when he deposed Stockwell Day. Harper brought Stewart-Olsen into his PMO in 2006. Three years later he annointed her senator for New Brunswick, presumably with all the attention to residency detail he lavished on Mike Duffy and Pam Wallin.
Not that it's in any way conclusive but Wiki lists her residence as Ottawa, the place she worked and lived for so many years before sliding into the Senate.
It sounds like, with her Ottawa-centric background, someone should look into how Stewart-Olsen meets the requirements of residence for a senator for New Brunswick.