Since ruby is so young, she probably is beginning to adjust to her new home. If she plays on the bed with you in it, it could be that she is delighted with being on the bed with you. Perhaps you could allow her on your bed at night as she will eventually settle down. Young kittens will often play while we want to sleep, but this kitten behavior should not last too long. I concur with the other post, that getting a litter mate or another kitten should help the situation. When I adopted Solstice, she would attack the other cats, run and hide. But when I went back to the shelter the next day and adopted her sister-littermate, Summer, she immediately changed her behavior and began to run around the house, chasing each other.