The former Zoey 101 actress, 19, gave birth to Casey Aldridge's child, daughter Maddie, in 2008. The couple announced plans to wed before calling off the engagement and splitting over the New Year.
Jamie Lynn Spears went on to date James Watson, a businessman 10 years her senior, but they broke up in May.
Now the teenager is back with Aldridge, reports People.com. A source says, "(They) are working on things between them."
The couple enjoyed a double date with Britney and her agent boyfriend Jason Trawick on Wednesday night when they checked out the Poker Face hitmaker in concert in Los Angeles.