If have 3 kids born in is and mom lives in us 10 years and came from prue, what is a way now for citizenship

There is no direct path to citizenship. She would first need to become a lawful permanent resident. There is nothing in the information provided that indicates she is eligible for lawful permanent residence. Simply having U.S. citizen children is not enough. One of her children could only petition for her upon reaching the age of 21. There may be options depending upon more facts. I encourage her to consult an attorney about her situation. In the interim, you can read more about immigration at http://myattorneyusa.com/immigration-to-the-usa.