I think that if you want sentences for kids only 6 years old, then they should be a bit simple and easy ones....As I have seen, that also reflect the meanings of the words.
PILLOW -- I am sleeping on a soft(etc) pillow, I have two pillows on my bed, My pillow is filled with feathers..etc
COLLAR -- The dog is wearing a collar, I bought a new collar for my dog, My shirt has a blue collar...etc
KENNEL -- The dog is sleeping in his kennel, The dog's kennel is made from wood, I tied the dog beside his kennel ... etc.
You yourself can make such kind of sentences, depending on the understanding of the children. Hope so it will help you.
(P.S. I AM NOT ANY ENGLISH TEACHER, i hope so that any teacher will help you better!)