Jennifer Garner and John Miller’s relationship remains strong amid her ex-husband Ben Affleck’s split from Jennifer Lopez.

“She’s happy with John,” a source tells PEOPLE of Garner, 52, one day after Lopez, 55, filed for divorce from Affleck, 52, in Los Angeles County Superior Court.

Hours before Lopez’s filing, which occurred on the second anniversary of their Georgia wedding, Affleck was seen returning to L.A. with Garner after they recently brought their oldest daughter Violet to college at Yale University in New Haven, Conn.

Garner and Miller, a California-based businessman, entrepreneur and author, began dating shortly after she and Affleck finalized their divorce in October 2018. The former couple were married from 2009 until they announced they were divorcing in June 2015, though they did not officially file for divorce until April 2017.

PEOPLE first reported that Garner was beginning to date again days after she and Affleck finalized their divorce in 2018. It was confirmed she was dating Miller just weeks later. Though the couple were seen spending time together on a number of occasions over the next two years, Garner said she was single in a March 2021 interview with PEOPLE. However, she and Miller were seen together several more times over the following two years. In February 2023, a source told PEOPLE that the couple had been back together for one year.

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Garner and Affleck share three children: Violet, 18, Seraphina, 15, and Samuel, 12. Prior to dating Garner, Miller was previously married to violinist Caroline Campbell, whom he divorced from in 2011 after six years of marriage. The former couple share two children together.

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Though Miller and Garner have been back together for well over one year now, the couple tend to keep their relationship private. Even when Miller joined Garner at an April 2023 premiere for her Apple TV+ series The Last Thing He Told Me, they did not pose for photos together on the red carpet. The pair were most recently seen taking a walk together in Los Angeles back in April.

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PEOPLE confirmed that Affleck and Garner recently took a trip to Japan with their children, though he did not appear in a series of photos and videos from the vacation that Garner shared on Instagram on Aug. 15.

Before Affleck and Garner brought their daughter Violet to college, the family also celebrated Affleck’s 52nd birthday together on Aug. 15; both Garner and Lopez were spotted visiting the actor’s rental home in Brentwood, Calif., according to photos obtained by Page Six.