The former child star, who played embattled comic Bill Cosby's youngest daughter Rudy in the hit sitcom, broke the news of her engagement on Instagram by posting a shot of her new sparkler.
She captioned the image, "Happy to spend not only my new year but my life with this guy!!! #BlessedBeyondMeasure."
Former American footballer Ed Hartwell, who was previously married to U.S. reality TV star Lisa Wu, popped the question on New Year's Eve (31Dec15).
The engagement news comes as Knight Pulliam's former TV dad faces a felony charge of aggravated indecent assault, amid allegations he drugged and sexually assaulted Andrea Constand at his mansion in Pennsylvania in January, 2004.
Cosby, who denied the accusations at the time, settled a civil suit with Constand, a former employee at his alma mater, Philadelphia's Temple University, in 2006, but police officials in Pennsylvania recently reviewed the case and issued an arrest warrant for Cosby on Wednesday (30Dec15).
The 78-year-old turned himself in to police hours after the arrest warrant was issued and was arraigned in a Montgomery County courthouse. A preliminary hearing has been scheduled for 14 January (16).