What does Meimei's mother mean when she says, "Is shame you fall when nobody push you" in "Rules of the Game"?

Falling down without a cause, no one pushing you, is being a coward.

This reference has to do with the decision Meimei (Waverly)  must make on whether to play competitive chess.  She does not want to bring shame on her family, in the event that she loses the game.  Family dignity, and not bringing shame is a component of Chinese culture.

Honor and respect are a very big part of Chinese culture, so Meimei is worried that she will embarrass her family if she loses.  Her mother makes it clear to her that not taking the challenge is the action of someone who is afraid of life.  She teaches her children the art of invisible strength.

"Most importantly, however, is the Chinese philosophy that Waverly’s mother teaches her when she is six years old. ‘‘The art of invisible strength,’’ a collection of Chinese ‘‘daily truths,’’ is a ‘‘strategy for winning arguments [and] respect from others.’’