https://www.peachcare.org/FaqView.aspx?displayFaqId=102
https://www.peachcare.org/FaqView.aspx?displayFaqId=101
https://www.peachcare.org/FaqView.aspx?displayFaqId=103
It says here for Peachcare a family of four can make up to $59,904 a year. You never know if you or your sister might need healthcare. See if you can be covered now and if your dad makes more money in the future and buys a family insurance plan, you can always de-enroll.
The way it worked for us in the past was we had to provide proof of current income and if the income or employment changed we had to let them know.