I have been privileged to have been the caretaker of an indoor
cat colony. I hesitate to say "owner" of cats, since I don't
think one can own a creature that is so noble and independent.
Here are my observations on the special ways of mother cats
and their kittens.

I have noticed that the females will often come into heat at the same time.
If they are bred, they will have their kittens at the same time,
and will raise them together. This would have survival value in
the wild, because if something happened to one of the mothers, there would
be other females with kittens who could care for the orphaned young.

The mothers generally go to a dark area, such as in a closet or under
the bed, to give birth. One exception was Katie, who had her kittens on
my bed during the evening and night. I had to stay with her, as she wouldn't
allow me to leave her. During the night her sister took the kittens,
all but one, into the closet with the other kittens. In the morning,
when the sun came up, Katie took one look at the sun, and took her
kitten to the closet. This was her first litter, and somehow she knew
she had to get her kitten out of the bright light, which can harm the
eyes of newborn kittens.

(By the way, this little guy was born all white. I thought he
would be a white cat. But within a few days he began to develop
darker points. He was a Himalayan, with blue eyes and chocolate
brown face, ears, paws, and tail. The only one in his extended
family.)

Mother cats have a special sound they make when they call their kittens,
kind of a "prrrimmp," and when the kittens hear it, they come running
to mom.

Litter mates generally stick together, even as they get older. They
sleep together, and usually do not go far from their "home base" when
young. Their mother typically moves them at least once when they are
quite young. They may do this when alarmed. One year, on July 5 (the
day after the 4th of July fireworks), I looked into the back yard and
saw a stray carrying a kitten to the house. She dropped him off and
went back and got two more, one at a time. My place is the safe
house for felines in the area. And they know that.

When the kittens are nursing, they and the mother purr. This can be
quite a loud sound, like a motor running, when they are all purring
together.

The females who don't have kittens sometimes help care
for the offspring of their sisters or mothers. Some of the males
seem to really love kittens as well, and help take care of them.
I have taken in some dropped-off kittens which were quite young,
about 6 weeks old, and the females, even those who have never had
kittens, will adopt them and mother them. The kittens will try to
nurse, even though the surrogate mother doesn't have milk, and she
will let them. And she will groom them and treat them as if they
were her own young ones.

If the mother is a good hunter, she will teach her kittens to hunt.
Squirt did this quite early with her kittens. Before they were old
enough to eat solid food, she would catch mice and put them with the
kittens, to give them the smell of mice, apparently. As they got
older, she would continue to catch game and give it to the kittens.
Eventually, by watching mom, they learned to catch their own. Some
of the males would do this as well, catching mice and giving them
to kittens.

One time a pair of Mallard ducks were in the yard. Squirt and her four
kittens tried to sneak up on them, slowly creeping closer and closer.
Until they got close enough to realize how big these birds were. Then
they got scared and ran back to the house. But soon they tried
sneaking up on them again, and got scared again and ran back. They
repeated this scene over and over until the ducks finally flew away.
It was hilarious.

I think kittens should stay with their mother until they are at least
12 weeks old. I know a lot of people put them up for adoption at 6
weeks old, but having observed cat families, I think it's better
for all involved to keep them together for that long. The kittens
will want their mother's milk and affection long past 6 weeks, and
the mothers seem to enjoy caring for kittens and teaching them
feline ways.