Would you consider staying off-site? We are going in November and are staying at the Lake Buena Vista Resort Village & Spa -- we got a 3-bd/2-ba with kitchen, laundry, etc. for $139/night. They have 2-bd units which would be even cheaper. You could give your daughter her own room and once she is in bed, you could hang out in the living room and watch TV, have drinks, etc. The hotel got great ratings on Tripadvisor.com and my cousin, who works at Disney, said she'd recommend it over some of the on-sites. I think it is within 1 mile of the Magic Kingdom. And it has a great pool area for toddlers.
http://www.lbvorlandoresort.com/