Hello Alison!  Welcome to the Disney Parks Moms Panel.  Disney's Art of Animation Resort is so amazing - I really think your daughter will love the incredible theming and fun vibe that this resort has.  However, like you've heard, the Little Mermaid section is the furthest from Animation Hall, the buses, and the Big Blue Pool.  If mobility isn't an issue, I would say that the approx. 5 min walk really won't be a problem.  It is an interesting walk, as you will walk through the Lion King section before arriving at Animation Hall. Personally, I love this resort so much - I love that it is so new and so true to the movies it is depicting - that I would stay there even if it means an extra bit of walking.  I would also request buildings 7 or 9, as they will be the closest over building 8.

Good luck with your decision, and I would be more than happy to assist you with any other questions you have while planning your Walt Disney World vacation.  Have a magical day!

Kristen