Angelina Jolie celebrates 51st birthday with her children; attends son Knox's graduation ceremony - PICS

Angelina Jolie marked her birthday with an intimate celebration, surrounded by her kids. The actress, who turned 51, was spotted as she stepped out with her children in Los Angeles.As per the Daily Mail, the Oscar-winning actress was photographed on Thursday alongside sons Knox, and Pax, as they spent time together on her birthday. Dressed casually in a grey sweater, trousers and spectacles, the star was seen stepping out of a car while her boys took over the wheel.Knox was hard to miss with his orange-and-red hairstyle, pairing the look with a cream-coloured shirt and white joggers. The teenager was seen helping his mother unload items from a vehicle, while Pax was reportedly seen chatting with his mom during the outing.The birthday celebrations reportedly coincided with another major family milestone, as Jolie was also seen attending Knox's graduation ceremony. As per social media posts, the actress was spotted taking her seat among the many parents and recording her son as he went up on stage.TikTok posts featuring Knox in his graduation cloak and cap, while accessorising his look with a flower garland and colourful prayer flags around his neck. As per the post, he gave quite the 'epic speech'. Interestingly, the clip shared by the handle @guarner97 referred to the teen as 'Knox Jolie' and not 'Knox Jolie-Pitt'.This comes after Knox's brother, Maddox, 24, hit the headlines last month after he formally requested the removal 'Pitt' from his surname and simply opted to go by Maddox Chivan Jolie.He is not the only one to have distanced himself from father, Brad Pitt. Shiloh legally dropped 'Pitt' from her surname and changed her name last year, while Zahara and Vivienne have also reportedly chosen to use Jolie rather than 'Jolie-Pitt' in public settings.Since filing for divorce in 2016, Jolie and Pitt have remained estranged and continue to be in a legal battle over their French vineyard.