I am the proud step-mother of 4 wonderful kittens! The babies are 4 weeks and 1 day old. I have 3 girls and 1 boy. All the babies are eating solid food, but 1. She is still only eating off her mother's milk. Her mother is trying to wean them, but she follows her around untill the mother gives in and lets her feed. The baby does play with the other's but she also sleeps alot more then the others and she is alot thiner. What should I do?