Reese Witherspoon marked Jennifer Garner's birthday with a sweet throwback picture

She captioned the picture: "Here's lookin' at you, Jen! Happy Birthday to my gorgeous friend #JenniferGarner who always laughs at my jokes and my bad dance moves! Love you! (sic)"

Meanwhile, Jennifer's friends threw her an intimate birthday party over the weekend.

A source said: “Jen arrived with a small group around 6:30 p.m., just as the sun was starting to set. The ladies started out at the bar area, and once everyone arrived, they were moved to tables along the railing overlooking the ocean.

"The tables looked pretty with little votive candles, hydrangeas and roses. A few of Jen's friends arrived before the party started to get everything set up."

Jennifer’s manager and publicist were at the party alongside Reese and some of the star’s “mom friends” also made an appearance.

The insider added: "Some of the girls were mom friends from school. Her manager and publicist were there as well."

Although Jennifer filed for divorce from her estranged husband Ben Affleck last week - over two years after the couple separated - she looked “happy” being surrounded by “people closest to her”.

The source shared: "Jen looked so happy to be surrounded by the people closest to her. She had the best evening and was so gracious. She gave a little speech and thanked everyone for coming. Everyone went out of their way to make Jen feel special and be there for her. Her friends adore her and think the world of her."