The couple attended Affleck’s daughter’s milestone event in Los Angeles on May 30

Ben Affleck and Jennifer Lopez supported his daughter Violet at her graduation ceremony on Thursday, May 30, amid talk of tension in their relationship.

Also in attendance at the Los Angeles school’s commencement: Affleck’s ex-wife and Violet’s mom, Jennifer Garner, 51, the exes’ other two children, Seraphina, 15, and Samuel, 12, as well as Max and Emme, the 16-year-old twins Lopez shares with ex-husband Marc Anthony.

Shortly after the event, Lopez was spotted happily chatting with her kids. “She seemed upbeat and engaged,” said an onlooker.

Photos published by Daily Mail show Lopez and Affleck holding hands at one point during the event.

Earlier that day, Affleck, 51, and Lopez, 54 — whose marriage “is not in the best place at the moment,” a source connected to Lopez previously told PEOPLE — reunited at a graduation celebration.