Note to parents, doors aren't safe

About two or three weeks ago, I was in the bathroom using the facilities.  I’ll try not to go too much further into detail, but basically I was sitting on the toilet.  And for some reason I can’t exactly fathom, I decided to close the door.  I never close the door.  Michael never closes the door.  Only when we have guests.  Maybe I just needed a minute or two away… Michael was on the sofa in the TV room and Calliope was running around somewhere.  Next thing I know, the door handle was twisting and the door popped open, but not very far.  I immediately yelled at Michael not to open the door to which he responded “I didn’t do it.  I thought you did.”  And we both realized that Calliope had done it.  Michael knew she was there playing with the knob, as did I now that I think about it.  But neither of us thought it possible that Calliope had done it.  She had never even tried as far as we knew.  So I pulled the door open a little more and there was Calliope smiling brilliantly, very proud of herself and excited to see she had started a game of peek a boo.  For the next ten minutes, Michael and I walked around dumbfounded excitedly discussing the situation.
That door has a glass knob on it.  Not a lever like our back doors.
Two nights ago, Michael came home and because of the construction next door, decided to go out the back and talk to one of the contractors about something.  I was in the front of the house doing something, who knows what.  I heard it as it happened.  The door cracked open and then a stumble.  Unlike the french doors that require a little more force, the side door to the stairs is much easier to open.  Calliope had grabbed the handle and pulled down, fell against the door and out of the house!  She was definitely not hurt, maybe a little shocked.  As were we!  The consequences of her going out the back or front doors are small in comparison to the back side door.  She easily could find herself in a very dangerous situation while construction is going on.  Once they are done, there will be a house next to us again, but right now the railing is minimal at best.  Just goes to show that these type of dangers can really sneak up on you.  We feel extremely lucky.  We are very aware of her surroundings and pay attention to all the hazards that could arise, but this one really came up out of nowhere.  Now we are on full alert that that door needs to be locked at all times.  This is hard though because there is no way to secure it if you just left the house through it.   Its just a handle.  But now we know, so lesson learned.