[Oh no, this is too cute. He's watching her mimic him, not saying anything about it, but getting that sometimes kids learn best by physically doing something instead of just listening. If this is going to help her remember, then all the more power to her.]

Yup. Instead of flapping some wings spaceships have jet engines. Those things control an explosion that sends them upwards and away from the planet's gravitational pull.

[He resists the urge to go into the engineering details of how spaceships work. If he wanted to explain more of them he'd need a bit of time to figure out how to explain it to her in a way she'll understand given her age.

For now he hesitates a moment, looking upwards. An idea is coming to him, but it's a little embarrassing saying out because it's - well, it's nice.]

... You wanna go flying?