Hi Kimberly!
Thanks so much for stopping by the Disney Parks Moms Panel.
Disney's Art of Animation Resort is one of my family's favorite resorts! Your 5-year-old is sure to have an 'Under the Sea' adventure while staying there. All of the Little Mermaid rooms are standard rooms and are located in buildings 7, 8, and 9. Buildings 7 and 9 are a tad closer to Animation Hall, the main building where Landscape of Flavors (the food court) is located.
I would normally choose a view of Hourglass Lake, however you said you wanted to avoid being near a smoking area. There are smoking areas along the pathway around the lake, so just to be safe, I'd choose Building 7 unless you really want a lake view. I also like the top floor, because it tends to be more quiet.
If you have any other questions, please come back and see us real soon. Have a magical vacation!
Tania