I live in Ottawa! Depends on what the person is interested in. Most of the museums are pretty good about being accessible, though I personally found I enjoyed the Canada Aviation and Space Museum the most, as I could get close to the largest number of exhibits. The Canadian War Museum, for example, really does try, but nearly everything is behind thick glass for obvious reasons. The Canadian Museum of History is similar in that respect. I never got to the CSTM before it closed, so I can't say anything about that.

Visiting parliament was worth doing for me, though probably mostly to get close to The Peace Tower. I've never traveled to any other location with a bell tower, so getting right near the bells as they rang out was worth it to me.

Never been to The Royal Canadian Mint, though it's on my list of things to do at some point. Depending on how it's set up, it could be really interesting, assuming everything isn't just behind glass, or if the guides are willing to let blind folks touch/hold any of the coins/bars/etc. They do have guided tours, so it's probably worth calling ahead if you want to try it. If you do, I'd appreciate knowing how it went! :-)

Never been to The National Gallery of Canada, and don't intend to go, for obvious reasons. But maybe if the people in your group have some remaining vision, it might be worth it.

As for food, I really don't eat out much because of cost. But my two go-to places are Kettleman's Bagel Co and Gabriel Pizza. Gabriel's has the best pizza in Ontario, and maybe even the country. Though you will pay a little more for it. After I moved from Toronto, it quickly became the only place I go on special occasions. As for Kettleman's, they make all the bagels fresh, right there in the restaurant. And they're so good! Plan on ordering them and eating them right in the restaurant while they're still warm, though. I found that ordering a dozen and bringing them home just isn't worth it; they don't keep well, even if you freeze them.