Hey there, Jean! Thanks for the question.
Oh how I love
Disney's Old Key West Resort. It's bright and light and just "feels" like Florida. I also think it has one of the few still hidden gems when it comes to restaurants.
Olivia's Cafe is a must do for me whenever we stay at Old Key West.
Disney Vacation Club has two room categories at Disney's Old Key West Resort. You can choose either a standard room or one near the Hospitality House. The buildings near the Hospitality House get you the closest to the marina, the main pool area, and, of course, the Hospitality House (which is where the front desk and shopping is). Those buildings are 11-14 and 23-26. If you have booked a room in the near the Hospitality House, my favorite building is 26. The walk to the main amenities is less than 5 minutes - even with two year olds, and it's also the first bus stop.
There is one thing I do want to mention, especially given your two tiny princesses. Most of the buildings at Disney's Old Key West do not have elevators. These include the buildings closest to the Hospitality House. If you are going to request a room in any of those buildings, you may want to request a room on the ground floor to avoid having to carry two tiny, tired girls up flights of steps at the end of the day. Buildings 62, 63, and 64 all have elevators.
In terms of bus stops - there are 5 throughout the resort. You won't be a long walk to a bus stop from any building.
Have so much fun!
Anna