Definitely The Running Stitch,
http://therunningstitch.ca, located in Kanata (west end of ottawa). Open on Sundays (12-4) too.
Other choices: out in the east end, Quilty Pleasures
http://quiltypleasures.ca/. In Carleton Place (20 minutes from the west end of town), The Pickle Dish
http://thepickledish.ca/.