Three Year Old in Cot

Kamryn slept with us last night after having what I am assuming is a bad dream as she was whining and wimpering but not actually crying. She was also thrashing and pushing me away when I went to her. Anyway in the mornings I never get out of bed when my kids do lol. I'm soooooooo tired in the mornings and when Kamryn sleeps with us she is usually up early. Today she got up and I could hear her talking and playing, I had both monitors on so I assumed she was in her room playing or something. Well I would hear Lauryn randomly laughing, babbling or crying and realized that Kamryn was in the room with her talking/playing with her. I decided to get up and check out the situation. Imagine my shock and surprise when I rounded the corner to see Kamryn sitting in the cot with Lauryn! I couldn't believe it! Then upon further inspection, Kamryn had piled every blanket Lauryn had in bed (which is roughly 6 lol) on top of her and was playing with her. I couldn't see Lauryn at all and then I had a mental picture of my three year old suffocating my baby (I knew she was fine as she was making noise). I quickly grabbed Lauryn and she hugged me probably thinking 'thank goodness you finally got here!' I simply told Kamryn she wasn't to get in Lauryn's bed again, it probably won't sink in, but she said ok. We will be latching the hook and eye now!