The comedy will focus on a recently divorced mother (Reba McEntire) who must raise her children while working to reignite her singing career.
Rue will play the upbeat, overly-friendly neighbour of McEntire's character Reba Gallagher, according to Deadline.
The actress starred in ABC sitcom Less Than Perfect from 2002 to 2006 and has since appeared on The Big Bang Theory and Rules of Engagement.
Damages actress Lily Tomlin was previously cast in Malibu Country as Reba Gallagher's mother Shirley.
The pilot is being penned by Kevin Abbott, who previously worked with McEntire on her sitcom Reba. His past work includes Golden Girls, Roseanne and My Name Is Earl.
ABC is developing a number of other comedy pilots, including identity-swap sitcom Prairie Dogs with Kal Penn, a new project with Mandy Moore and a remake of UK series Only Fools and Horses.
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