The Full House star, 28, is expecting a baby with boyfriend Monty Coyle. Sweetin has a 2-year-old daughter, Zoie, from her previous marriage to Cody Herpin.
In 2009, Sweetin released a memoir, UnSweetined, documenting her past drug addiction and alcohol abuse following the end of the sitcom in 1995.
"They're happy," Sweetin's rep told People, adding that she "is in a good place. ... She's looking forward to moving on with her life and she's just happy to be a mom."