Q: Parent doesn’t arrive at pickup location on time.  Do I have to give child to her?

This is very fact dependent.  But my advice is always to take a reasonable approach.  If a parent is scheduled to begin parenting time at 3PM and shows up at 3:30PM, you should permit the time.   Even without a valid excuse, it is best for the child to maintain continuity in his/her schedule and to see the other parenting regularly.  If the parent arrives so late for parenting time that the time is almost over (ie 30 minutes before drop off time), or when the child has already immersed himself in another activity, you may ask the other parent to consider another day.  Remember that this is about the child and his/her relationship with the other parent.  Be flexible and try to ensure that the child has that time as often as possible.  However when this does become a constant problem, you can also address is formally to resolve it (maybe a later start time).