Here's what I wrote to another famiy visiting Ottawa:
Your list of dos is a good one - here are a few more:
If you have a car while you're here, you might want to take a drive and then hike through the gatineau hills (your hotel can give you maps). You could go down to Dow's Lake at the far end of the canal from you - gorgeous gardens, and you can rent peddle boats or canoes.
I've never done this tour but it's supposed to be fun - "Haunted Walk of Ottawa. Mon-Wed at 8 p.m. Thurs-Sat at 8 p.m. and 9 p.m. Meeting place is in front of DArcy McGees, at the corner of Elgin and Sparks Sts. $12 adults, $8 students/seniors and free for kids 10-and-under when accompanied by an adult. Tour Director Glen Shackleton blends local history and ghost stories into a 90-minute walk. Tours often sell out in the summer, so registering in advance is recommended, by calling 613 232-0344."
At the national gallery, there's a Renoir exhibit this summer. They do have a kids part where they can do art and have it hung in the gallery. The Children's Museum, inside the Museum of Civilization, and the dinosaur exhibit at the Museum of Nature. The Museum of Science and Tech is a good, hands-on one for the kids, but a 15 min drive from your hotel.
Walking through the market on Sat or Sun is fun, usually lots going on, buskers etc. Kid friendly restaurants: In the market, the Lone Star is loud, fun, tex mex with yummy fajitas; Blue Cactus is good for kids as welll Zak's diner is a fun spot for kids too. My dd LOVES Elgin Street Diner, close enough to our hotel, on Elgin St (not the market). You have to "upgrade" to poutine here if you havn't tried it!
PM me if you need any more info. Have a great holiday!!