Funny girl Nia Vardalos by no means intended to turn out to be a spokesperson for any cause, and valued her privateness. But after providing counsel for a girl grappling with the identical infertility considerations she’d needed to take care of, she knew she may make a difference. In “Fast Mother,” Vardalos shares her story. Here’s an excerpt.That is the prior to-I-Start-Typing Prologue I’m apprehensive. To be honest, I’m sweating like I…