DePrisco, 58, popped the question to Niemi, 57, on Christmas Eve, her rep tells Us. The couple has been dating for over a year and first met through mutual friends.
Swayze -- best known for his work in the films Dirty Dancing and Ghost -- died at the age of 57 in September 2009 after a battle with pancreatic cancer. The late actor was diagnosed in January 2008 and had been undergoing chemotherapy at the time.
Swayze and Niemi wed in 1975 and had been married for 34 years. The two first met when Niemi took dance lesson's from Swayze's mother, Patsy, who died in September at the age of 86.