High School Dad Concerned About Back Child Support

I am 18 in my last year of high school. My son is seven months and my mom has been providing support for him as well as purchased him some insurance on my behalf. My mom wants me to concentrate on finishing school so I can go to college and obtain a good career not just a job to take care of my son. In the court of law is this considered legal that my mom is doing this until I finish high school? Will I be made to pay back the government if she receives assistance and medicaid.