One of the questions I am frequently asked is whether this breed is a good one
to have when there are children in the family. The answer is a qualified yes,
depending upon the children. The average Cavalier is so affectionate and forgiving of the slightly rough treatment that can be handed out by children, but his patience is not endless.
A puppy usually goes to his new home at the age of 8 weeks, when he weighs between three and five pounds. If there are toddlers or small children in the family, they must be supervised when playing with the puppy, and they must never be allowed to pick the puppy up and walk around with him. I have seen a few disasters as a puppy wriggles and jumps out of a child’s arms and is injured in
the fall. The floor is the perfect place for child and puppy to be together, as it is safer and less intimidating for the puppy to have someone at his own level.
When you see that the puppy has had enough play with the child and is beginning to back up or run away, pick him up and put him in his place of refuge, the crate, for a nap or quiet time.
I always ask a family to visit if they are interested in purchasing a puppy, and the reason is that I want to meet the children to assess their behavior with the dogs. Children who pay attention to my instructions on how to approach the dogs and who are gentle with them will usually treat a puppy with respect.
Little horrors who grab at the dogs and run around making loud noises with no discipline from their parents will probably end up making a puppy nervous.
The temperaments of some puppies are more suited to children than others. All ranges of temperament in the Cavalier should be sweet and loving, but they vary, just as temperaments do in a human family.
 The extroverted, confident puppy will be happy with the noise  activity generated by a house full of children, while this situation would be intimidating for the quiet, submissive puppy, who would be better suited to a home with adults only