Cat made it back 13 miles to my house!!

Well about 2 1/2 months ago we found a young cat that had babies in the lot next to our house. After about a week of feeding the mom she let us see the babies. We brought them home but them in the garage and took care of them. One night the mother just kept nursing the babies and then she went away to the other corner of the garage. She was not looking to good so my aunt took her to the emergency pet hospital they found she had an infection and opertated on her. We brought her home and let her out by the kittens who could now see and were ready to play. The mother tried to nurse but could not give any milk so we bottle fed the kittens. Well the kittens got older and each got there homes one at a time. We kept one and the mother. The mother did not get a long with our dogs so she was not exactly good to have around for the dogs. My aunt found someone that had kittens and the mother left them. SO we gave the cat to these people who live 13 miles away on a ranch. She took care of the kittens and was happy at her new home.
Today the mother cat came home 13 miles from the country into the city. She went right to the food and then wanted in the house. Where she started hissing at her babie that we still have.
I called the people we gave her to and they said she was gone about a week ago after the last kitten left. She was just not the same cat after the kittens left from what the told me.
I have heard of dogs doing this but cats. I was amazed. I figured I would share it seemed kinda odd.
The picture is of the kitten Dokota