Kittens can’t regulate their own body temperature. That’s why they pile up.
Cats see us as colony members.
Masha saw a kitten that was on its own, no mommy, no other kittens to cuddle with. She instinctively knew that was a cold kitten. She knew that a kitten alone on a cold night was very likely to die. Because a kitten would have died too.
So, all she was doing was what any good colony member does - protecting the abandoned kitten. Then when the abandoned kitten’s mommy didn’t come back, she called the rest of the colony for help.
People have this bizarre idea that housecats don’t have a social sense. They do, and it saved this kid’s life. And possibly Masha’s too, as life on the streets is dangerous for a kitty.
We say “good dog” all the time, but Masha was being a very, very good cat…not just by human moral standards but by feline ones.