The surest way to get the Girl to do something she’s reluctant to do? Turn it into a game.
Say you’re on the third floor of a building. (Which would be the second floor in Poland — the ground floor doesn’t count I guess.) Say you’re not keen on using the elevator because it’s so painfully slow. Say the Girl complains about being tired. How do you get her to go along with your scheme to use the stairs?
Simple. Turn it into a race.
It helps if Nana is there to be the opponent, of course.