The 'small celebration' took place at their Brentwood property which the couple used to share before their separation in 2015.
A source told a leading publication that Ben was present at the celebration. The source further added "Seraphina had friends over for cake.
She got lots of gifts".
Despite making their split official by filing for divorce in April last year, the stars have remained on good terms to continue to be present for their kids as parents. The duo has three kids together, Violet, aged 12, Seraphina, aged 9, and Samuel, aged 5. Ben and Jen have been married for ten years before splitting in 2015.
While Ben has been seen out and about with his girlfriend Lindsay Shookas, Jennifer is yet to move on with someone.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)