Mary, what a great photo and congratulations again on your engagement! We took a peek at that bar in the Frontenac and it is beautiful. I wanted to look at it because it is mentioned in Louise Penny's book Bury Your Dead, which is set in Quebec City. If it hadn't been so early in the day we would have had a drink there!
Isabel, it is definitely worth a day trip to the Montmorency Falls. They are taller than Niagra Falls, but not as wide. Very impressive! The falls are close enough to the city that you can bike to them (as ambitious Mary & Gentleman Friend did), or take a cab (like lazy Mr. & Mrs. Debora).
We also took a guided tour of the Citadel and learned about Quebec's military history. We spent a lovely afternoon at the Musee de la Civilisation. Other highlights included the Place-Royale, a beautiful square considered to be the birthplace of French-America. The Quartier de Petit-Champlain, with its shops and cobblestone streets. Strolling on Terrasse Dufferin by the Chateau Frontenac.
Feel free to PM me, too, if you have any questions. Have a wonderful time!