RHOSLC Star Mary Cosby's Son Robert Cosby Jr. Dead at 23

"It allowed him to sober up and start thinking clearly," Simms told the outlet. "He's looking forward to doing positive things. The difficulty is that he was slow to recognize the dissolution of his marriage. But now he understands the relationship is over, and he's moving forward."

Robert—who was facing 14 charges—had pleaded guilty to eight in December, according to court documents obtained by People, including felony property damage or destruction; violation of a pretrial protective order obtained by his estranged wife Alexiana Arian Smokoff, 21; and criminal trespass on a dwelling with intent to cause annoyance, injury, or fear.

Following his return home, Mary—who shares Robert with husband Robert Cosby Sr.—celebrated the news. Alongside a snap of her son, she wrote on Instagram Feb. 7, "Love you all. My beautiful son.. I love him sm."

The reality star had previously reflected on her son's legal troubles during RHOSLC's season six reunion last month.

"I'm not worried about him," Mary said. "I know he's somewhere where he’s not using. At some point, I have to step back so that he can learn and he can make his own decisions, and unfortunately, he's learning the hard way. But I'm OK with it."

During his incarceration, Mary had spoken to him on the phone daily, though she couldn't bring herself to see him behind bars.

"I don't want to look at my child behind a glass," she added. "He calls me every day. I'm basically preaching to him. I'm like, 'You're going through this, but you have to realize that God is allowing it, and if God allowed it, then it's for your good. This will help you to change, and you gotta change.'"

For a closer look at Mary's family, keep reading.