With your kids you should really head over to the North Side and go to the children's museum. It is a wonderful museum and my DD could (and has!) spend all day there.
How long are you planning on being there? There are so many neat neighborhoods to explore if you have the time. Oakland and Shadyside are my two favorites. Oakland is a college community with tons of shops and resturaunts and it also has Phipps Conservatory.
Fifth and Forbes avenues, Pittsburgh's two main east-west traffic arteries, pass through Oakland, with bus stops on nearly every corner. Most Oaklanders get around by bus or by foot, lending a true "city" closeness and atmosphere. Spend a few hours in Shenley Park if you have the chance.
You also should go to the Strip District- it is within walking distance of donton (that is how you say it ya know!) and has tons of vendors selling ethnic foods, fresh fish, veggies, homemade cheeses, etc. If you're heading to the Strip for a morning of shopping, be sure to stop in at DeLuca's for a good, hearty breakfast or one of the Strip's good coffee shops. Lunch and dinner offer a number of options, including Primanti's where the overstuffed sandwiches feature the cole slaw and French fries packed inside with the meat and cheese. . The Klavon's Ice Cream Parlor is another popular spot, with its original fixtures, stools and marble soda fountain counter and is a blast for kids.
I could recommend so many things for you to see and do! I absolutely love Pittsburgh, it is my hometown, and I try to promote it as much as possible. If you have any questions, pm me and I will try to help you help!