The kittens mothers has been missing for a week. I must be their mother for a while

The cute tiny kittens. Unfortunately, their mother has been missing for a week. I think the kittens are 68 weeks old. I found the kittens who lost their mothers at the parking garage gate of the site. This place is too dangerous for them as there is a car entrance and exit. I moved them to a safe area. It s not very far. I just moved them 30 meters forward. I hope nothing bad happened to the mother cat. I will be the mother of the kittens until the mother cat returns. As the days go by, I worry more and more about the mother cat. ,kittenrescue, catrescue, adorablepaws, luckypaws I feed the kittens with breastmilk substitutes, wet cat food, dry cat food and water. And with love. I ordered a cat house for kittens. Soon the kittens will have a cat house. I feed them every 4 hours. I help them with their toilet needs. I created a safe environment for them in the garden of the house I live in. They were checked by a veterinarian. Everything is OK. Except for the one thing missing from this happy famil