Robison's spokesperson revealed that the banjo player will give birth in September, according to People.
"[Emily is] excited," Robison's representative told the magazine.
The baby will be Robison's first with boyfriend Strayer.
She and ex-husband Charlie Robison are also parents to 7-year-old twins Juliana and Henry as well as 9-year-old Charles.
Emily and her ex-husband divorced in 2008.
The musician is a founding member of the multi-platinum-selling Dixie Chicks, who have been on a recording hiatus since 2006.
Watch The Dixie Chicks' 'Not Ready To Make Nice' music video below: