I have lost many dogs, cats and two large parrots over the years and they are all different, with unique personalities. A new pet is just that. A new pet. A new pet can never replace a pet you have lost. They are totally new and themselves since every animal is different. Your new kittens are very cute. Hope you enjoy them. I know the stillness and quiet in the house after I lose a pet is unbearable, and after grieving a bit I am ready to welcome another one.