Moms the word gave some good advice. You might want to consider doing 2 days at MK, but spliting them up (one day there, one at 2 other parks, park hopping, and last day at MK.)
In addtion at MGM hit the "Honey I shrunk the Auddince" playground set. MGM has good shows for little kids that shouldn't be missed (Little Merrmaid and Play House Disney, but it is lacking in attractions that you can go to any time and don't need a show time for. If you want to go from MGM to Epcot there is a boat that takes you right there (by way of S&D, Y&B and Boardwalk.)
At AK don't miss the dinoland bone yard playground (closing for rehab some, not sure when) and trisauratops spin.
Since you have park hoppers if MK closes early, head over to Epcot for the evening too. (always open until 9:00pm)
Do a charter meal (CP at MK is always good, Pooh and friends, we like lunch less money) but there are many to chose from.
Don't miss the down time places (playgrounds ect... there are some at each park.) At night the light up sidewalk in Epcot on FL is great for 2 year olds.
Have fun. If it is only you and your DD going to the parks, be sure to do a trip in later where hubby gets to go also. She (and you) will want to share the Disney Magic with him. (and spend a week so you can do it all.)