Why was the actress who played Becky from the tv show 'Roseanne', replaced?
The actress who played Becky, Lecy Gorenson, left to go to college. http://en.wikipedia.org/wiki/Lecy_Goranson
The name of the actress you are referring to is Lecy Goranson. She left the show because she had to leave for college at Vassar College, and she found it difficult to balance both at the same time.