The 23-year-old reality star had entered a facility due to stress and depression earlier this month, reported Us magazine.
During her stay in rehab, her divorce from second husband Jeremy Calvert was finalized, giving Messer custody of the pair's daughter, Adalynn, two, while Calvert will have visitation rights.
Messer is also mother to twins Ali and Aleeah, five, with her ex Corey Simms.