Obviously it depends on your taste and palate considering the different cuisines from around the world. So from what I've experienced...
San Angel Inn - amazing atmosphere (#1 in my book) but about average for Mexican food. You can see a volcano in the distance, and maybe even the Gran Fiesta Tour boats coming and going.
Akershus - food was not to our liking, but it's a princess character buffet and if you're daughter is into that, she won't even be paying attention to the food!
Biergarten - lively and fun dinnertime show with buffet, one of our favorites of the WS for the atmosphere. You will likely be sharing a table with other parties though.
Teppan Edo - Japanese hibachi at shared tables, not much different than local hibachi restaurants here. So I'd skip in favor for...
Tokyo Dining - more authentic choices, quieter atmosphere because it's less popular and people don't seem to know it's there. Awesome views of the WS.
Marrakesh - authentic food and atmosphere, complete with a belly dancer. We prefer...
Spice Road Table - more though. For the waterfront views, lovely presentation of food (entrees not tapas), and awesome desserts.
Chefs de France - a homerun for food in our opinions. The restaurant itself is nothing to shout about other than it's refined but a little busy, but the food...the desserts...wonderful!
Rose & Crown - hearty eats, indoor or outdoor seating, can get a little rowdy. Not sure a 2 year old would care for it.
Le Cellier - signature dining experience, good food, but again, probably not for a 2 year old.
So...in conclusion, as I don't know what your daughter likes to eat, I'm going purely off of atmosphere for your party...San Angel Inn, Akershus, Biergarten.