Can a mother file for Medical when the father of a child is already providing ins.?

I've have been paying 4 health insurance 4 my daughter for 10 years now @ my place of work + providing monthly funds to her mother that we both agreed on ( did not have to go to court). I've found out that she has Medi Cal for my child, how is that possible? Can this hurt me in the future? Should I be worry? What is the worst that can happen?