Explain the concept of lift in regards to an airplane, but explain it like you would explaining it to a dog.
An example might be: You are inside a small closed box attached to leash with large dogs on each side and suddenly open the door releasing them outside where there is no way for them to climb back up! The idea behind lifting (and other similar concepts) can also apply to people as well who have disabilities that prevents them from climbing something! But most importantly... Lift your K9 pals feet before walking any distance and never ever push too hard or make her walk when tired