The 50-year-old stepped out near her LA home on Tuesday wearing an off-duty outfit consisting of a black pleated skirt and beige cardigan – but it was her jewelry that stole the show, with the sparkler reported to be an eternity band given to her by her boyfriend John Miller.
WATCH: Jennifer Garner sparks engagement claims with telling new jewelry
Jennifer has been dating businessman John since 2018 after her divorce from Ben was finalized. They briefly split in October 2020 before rekindling their romance earlier in 2021.
The 13 Going on 30 actress and father-of-two John have never commented publicly on their relationship, but her former Alias co-star Victor Garber – who married Jen and Ben back in 2005 – shared his opinion on her relationship.
"I have [met him]. I think he's adorable," Victor told Us Weekly in 2019. "They’re great! What's wonderful is they're taking their time and they are just enjoying each other's company.
"Her priority is her children. That's it. She's focused on that. She's remarkable … She's happy."
Jennifer stepped out with a diamond on her finger
The mom-of-three - Violet, 16, Seraphina, 13, and Samuel, ten, who she shares with Ben – opened up on the pressures of dating in the limelight on the Tell Me More With Kelly Corrigan podcast, admitting that there was often pressure to get engaged quickly.
"If it's true and you are starting to be serious with someone and [the press] start saying, 'Well, when are they gonna be engaged?'" she said, the same month she and John first split.
"It's almost like you just want to get there so that you can complete that and just maybe it will die down for a second. "And then it's immediately, 'Trouble in paradise.' And it becomes almost a self-fulfilling prophecy."
Her ring is reported to be an eternity ring from boyfriend John
Jennifer's appearance comes after Ben tied the knot for a second time with new wife Jennifer Lopez in August.
The happy couple exchanged vows in front of family and friends at Ben's incredible $8 million, 87-acre Riceboro estate in Georgia after legally marrying at the Little White Chapel in Las Vegas in July.
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