At that age my DD really liked the Aquarium of the Americas. The fish were brightly colored and move enough to catch and keep her attention. The weather should be really nice while you are here so a steamboat cruise or the zoo would be fun outside activities. Mardi Gras world is a great way to see the floats and get some history about Mardi Gras. You could definitely spend a day just wandering around the French Quarter- Jackson Square (lots of street performers and artists), a buggy ride through the Quarter, the Cathedral, the Cabildo, or the numerous shops and art galleries.

You should definitely go walk around city park - maybe have a picnic under the oak trees. Also there's a great sculpture garden, botanical garden, an art museum, and a lake to walk around. I live right across the street from city park and my LO and I spend many mornings and afternoons (when its cool enough) exploring the park. There's also a small amusement park and next to it is a place called Story Land which has a bunch of sculptures/slides/towers themed to kids stories, which I plan to take my LO to see once she's a little older. Have fun!

November is a great month to visit New Orleans.  The weather should be nice and mild.  Audubon Zoo is absolutely beautiful and really fun for the kids.  The Insectarium is really cool.  The World War II Museum is awesome.  Audubon Park & City Park are also really great.  I hope you have a great trip!