The telefilm will launch "Mary Jane" as the network's first original drama series, set to debut with eight episodes in January.
The movie centers around a woman who wants more for her life. With demands of her work, and caring for an ailing mother and pregnant niece, Mary Jane is struggling for more freedom.
"She wants more independence for her family so she can go back to just being a daughter and sister as opposed to a caregiver, which changes the familial dynamic," Union said.
In a recent interview with Access Hollywood, Union credited Kerry Washington's performance on "Scandal" as an inspiration to her work as "Mary Jane."
“Kerry does such an amazing job. She set the standard so high,” Union, who also auditioned for "Scandal's" Olivia Pope, said. “I got this opportunity and now I wanna run with it. But it’s because of Kerry."