I don’t know if it’s relevant or not but:
Mabel is afraid of heights.
And what happened in the last episode?
She was put into a situation where there was antigravity - a situation where she was literally clinging on for dear life as everyone/everything was lifted up!
She could have easily avoided her fear by pressing the button. But in the end, when she trusted Stan, she let go and was gracefully lifted up into the air.
Again, I’m not sure if it’s entirely relevant, but it’s worth mentioning.
It’s just one more factor that proves how brave she was in that scene.