I think you are trying to convey too much information in tags. There's no useful reason to separate the subject of kittens from cats.
Tags are supposed to organize content to help categorize broad areas of interest. But trying to further label the animal by its stage of development? That's is being overly pedantic and too specific for tags.
The question is about [cats]; tag it "cats." That's the people you are trying to reach. If it were about weaning, you would add the [weaning] tag. If you want to map kittens to the subject of "cats", that's fine. But don't use tags to create this pseudo-hierarchy of categorization from cat > tomcat/queen > kitten > clowder. That isn't helping anyone find this content (as evident above).
Adding layer upon layer of tags mapping cats/dogs/cows/deer/fox/chicken/pigs/hogs/mice to kittens/puppies/calves/fawn/cub/kit/hatchling/chick/piglet/shoat/farrow/pinkies/fuzzies/hoppers/weanling/adults/ — you're not helping organize your content. You're only losing stuff over pedantry.
You're trying to convey too much information in tags. Lose them all and start tagging your questions by what they are actually about. The details should be described in the body of the question.