I understand that. I do. But what is revenge going to cost you? Your husband?
You provided all of these years of insurance because that is what the court required.
She only WANTED to work part time? Or did she want to be a mother to her children?
Your vindictiveness is only going to cause greater problems in the family. With this attitude you are only going to cause a rift that may not be reparable. It is quite possible that the medicaid, according to your state, was the primary insurer, and the father's insurance was the secondary. Meaning that whatever medicaid did not cover, her father's insurance was required to cover.
I really feel sorry for this child, in all honesty. She has a mother and a step-father that are able to provide for her financially, even though the step-father is not required by law to provide for her, but her mother is using the system in a way that is acceptable. Now she has a step-mother who is vengeful and vindictive in that she does not feel that the biological father should provide what he is required to provide. My heart aches for this child.