My boss has no kids and lives for work, so it’s hard for me to request time off for a parent-teacher conference, a recital or the like. Would it be so bad to just say I have a doctor’s appointment?

It’s not so much that a little white lie for a little work life accommodation is so bad—though it’s always nice to avoid lying, for many reasons. It’s that your boss should be able to handle these kinds of requests. If she is as unfamiliar with the scramble and demands of working motherhood as you say, she should get familiar. If everyone tiptoes around her, fearful of disrupting the bubble of her own lifestyle choices, how will she ever become a good manager? Ask now, and others will follow.