Peggy actually managed to survive a great fall. In real life, she would have been liquefied as soon as she hit the ground.
Hank says "Helen Keller was largely useless but look how we remember her, First Lady of the American Stage." It was Helen Hayes who was given the nickname "First Lady of American Theatre".
This goof may be intentional to show Hank's limited knowledge of theater, and because he was thinking of The Miracle Worker, a play about the life of Helen Keller.
Animation error: The blocks on the mobile rotating over GH's crib transform and change color as they rotate.
While telling Hank why she thinks she jumped, Peggy's mouth stops moving but she continues talking.