(written from a Production point of view)
Sandra Nelson (born 29 December 1964; age 54) is the actress who played Marayna in the Star Trek: Voyager third season episode "Alter Ego" and Tavana in the Star Trek: Deep Space Nine fifth season episode "Soldiers of the Empire". Her dress from "Alter Ego" was later re-used by background actress Fedra Thompson in the episode "Concerning Flight" and sold off on the It's A Wrap! sale and auction on eBay. 
She was a regular cast member on the soap opera The Young and the Restless from 1997 through 1999. However, the majority of her credits from the 1990s are composed of made-for-television movies. These include 1993's Moment of Truth: A Child Too Many with Stephen Macht, 1994's Voices from Within with Corbin Bernsen, 1996's Brothers of the Frontier (with Star Trek: The Next Generation star Jonathan Frakes), and 1996's Run for the Dream: The Gail Devers Story (with John Schuck).
In recent years, however, Nelson has branched out into motion pictures. She had roles in the 2001 film Life as a House, (featuring Star Trek: Enterprise star Scott Bakula and DS9 guest actor Art Chudabala), and the 2004 film De-Lovely. Both films were directed by her father-in-law, Irwin Winkler. She also appeared in the 2002 thriller Enough (with William O. Campbell, Bill Cobbs, Bruce French, and Jeff Kober) and The Wolf of Wall Street.