First fall

It was 2am when I heard the "kolok-ko-ko". Evangeline fell off from the bed!!! OMG! She started crying uncontrollably. But, luckily Daddy was sleeping on the mattress on the floor where Eve landed on. Her head hit the bed frame, that explained the sound we heard. What actually happened??? At about 12plus mn, Eve was latched on Mummy lying side by side on the bed. After a while, we fell asleep and nobody carried Eve back to her cot. I also totally forgot that Eve was  still lying by my side. How did she fall? We still do not know but we were speculating that she might have rolled over to the other side or Mummy accidentally push her over the edge! So poor Eve...