Connecticut Law states as follows: "(b) If there is an unmarried child of the marriage who has attained the age of eighteen, is a full-time high school student and resides with a parent, the parents shall maintain the child according to their respective abilities if the child is in need of maintenance until such time as such child completes the twelfth grade or attains the age of nineteen, whichever first occurs. The provisions of this subsection shall apply only in cases where the decree of dissolution of marriage, legal separation or annulment is entered on or after July 1, 1994."
It also states that the age at which support stops can be modified/changed by a separation agreement or divorce. What do the divorce papers say?
Here is much more info:
Child Support in Connecticut