Sandra was the daughter of an Alvin Newcastle, who befriends Sophia before she learns that he suffers from Alzheimer's disease in the Season 3 opening episode of The Golden Girls titled "Old Friends". The part of Sandra is played in the episode by actress Janet MacLachlan.
In the episode "Old Friends", when Sophia meets a fellow retiree named Alvin Newcastle at the oceanside boardwalk near the girls' home, and who resides in the nearby Ocean Mist Retirement hotel, they quickly strike conversation and seem to develop a close bond. Later that week, Dorothy and his daughter Sandra follow the two, being Alvin and Sophia, to the boardwalk; Sandra then confides in Dorothy that it's a daily struggle for her and her husband with looking after her father Alvin, who suffers from Alzheimer's disease, and about the first time that he wandered off aimlessly from her home, which forced her to take off of her job, in taking a leave of absence, to look after him.
At episodes' end, it's revealed in another night time boardwalk visit by Sophia and Dorothy that Sandra was planning to send her father to New York City,to live with her cousin, who's a doctor who knows how to take care of him better.