I am a fourteen year old girl that is five feet elven inches tall and have size thirteen feet How can I get these flippers to stop growing?

You are very lucky to have the size feet that will support your frame, if you had small dainty size 6 or 7, you would look lopsided when you walk, so stand up straight and look regal! No one will ever look down on you!. Your feet will stop growing when they are ready, which will be very soon!