"Love these ladies," the actress captioned the post. "Celebrated this beauty last night. Happy Bday JA! We all love you sooo!"
TMZ said Aniston's ex-husband Brad Pitt also attended the event. The actor avoided paparazzi but was spotted from behind as he entered the building.
"Basically, every single person who Jen loves attended. That included Brad," a source told People. "The party was a celebration of Jen's life."
"Brad, for long, was a very important part of Jen's life," the insider said. "She was very happy that he showed up. Many of his close friends were at the party too."
Aniston and Pitt split in January 2005 after four years of marriage and subsequently wed Justin Theroux and Angelina Jolie, respectively. Aniston and Theroux called it quits in in February 2018, while Pitt and Jolie split in September 2016.
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