Sandweiss was born in Detroit, Michigan, and is a graduate of the University of Michigan. She gained notoriety in the 1981 horror cult-classic The Evil Dead, playing Ash Williams' sister Cheryl. Afterwards, she went on a hiatus from acting for over 20 years.
Sandweiss reprised her role as Cheryl Williams in the sixth episode of Ash vs. Evil Dead season two. The character being reborn as a deadite after a kandarian demon possesses a photo of her. She also makes a brief cameo as Cheryl in the season two finale.