The babysitter is always late.
What to do: Bring it up gently
If your sitter tends to be tardy, be very clear about your schedule when you call to book her: "We're seeing an 8 o'clock movie, so we have to leave the house no later than 7:30." You can also build in some extra time by asking her to arrive 15 minutes earlier than you need her. Let her know that you won't tolerate last-minute cancellations: If she has to bag the job, she'll need to arrange for a backup sitter (a friend or sibling you've previously met and approved) on her own.