It's all up to her really. Raja easily did 2 miles when he was her size. He'd probably keep going too if I wasn't ready to pass out on the couch!
I carry water dispensers for them on our long walks and always on hot days. We have 2 - both work by popping in a standard water bottle and has a little cup for the dogs to drink from.
The wonderful thing about our dogs is when they get too tired (mine let me know this by plopping down in the shade and won't budge) they are small enough to be comfortably carried all the way back home.
