Unforgettable experience

I had never encounter such a scary but funny experience before. Yesterday my daughter wanted to take her story book from the bedroom upstair and she asked me to accompany her to the room. I was lazy to walk upstair and hence asked her to go up by herself. After a few minutes later, i heard her yielding me from the room, so I went up to check it out. To my surprise, she was locked inside the room. She was not able to open the door, whcih i suspect she has locked it accidentally. The locked is somehow unreliable and my mom has encounter similar issue before (it was my nephew's bedroom actually). My sister-in-law quickly rush to get the room key while i tried to comfort her by talking to her. Luckily she was calm and not crying, thanks god for that! However the key can't open the door, it was stucked somehow. I become more and more nervous. How are we suppose to get her out??? We try to climb out to the balcony from the room next to it and see if we can get into her room,  but you know what, the window's grill was locked and the key was inside the room itself!! Oh no, what to do next? While we were out of ideas, suddenly my dad opened the door with the key....Thank god, we rescused her finally :) What a scary but funny experience we have had...