The Promise (1979)

Two college students, one from a rich background and the other from a poor one, decide to elope. They are involved in a serious car wreck that severely disfigures the bride's face. Her mother-in-law offers to pay for the necessary surgery for her, but only if the girl will leave her husband--the woman's son--and stay out of her life permanently. What comes after that is something none of them expected.