I have a baby gate at the top of the stairs with a lock on it. She is 89 years old and has decided it is OK to climb over it to go down the stairs whenever she wants. When I explain that she may get hurt by doing this, her response is "I didn't get hurt so I will do it." How can I stop her from climbing and possibly tumbling down the stairs? Is there maybe a device I can use on the gate to alert me that she is doing this? Bells don't seem to be working.