Does every mother, every parent feel like this when their child faces new milestones? Nervous, excited, unexplainably fragile? Our path to parenthood was perhaps longer, more complicated than some. Does that make a difference? All I know is, being a parent is simultaneously amazing, and hard, buoyant-brilliant, and mountain-rugged climb. Today, our eldest took her first small black-sneaker-clad steps to her school career,beginning kindergarten. Some reflections on my complex feelings below, in a form of letter to other parents…