Reese Witherspoon celebrated her 40th birthday on Saturday that has a private performance by Taylor Swift plus a duet with Keith Urban.

The Legally Blonde star marks this milestone on Tuesday, but her family helped her enter into the party spirit a bit early by throwing a major bash in Hollywood a few days ago, using a string of celebrity friends attending.

Guests with the event, held with the Warwick, included Kate Hudson, Matthew McConaughey, Robert Downey, Jr., Courteney Cox, Tobey Maguire, Jason Bateman, and Jennifer Aniston and her husband Justin Theroux.

Nicole Kidman seemed to be spotted in the party, where her husband Keith was section of the night’s entertainment, alongside surprise performer Out of the woods singer.

Birthday girl Reese, who arrived with husband Jim Toth, shared her excitement as she headed towards the bash inside a Snapchat video back with her mum Betty, who has been featured nodding because actress asked, “Are you gonna get crazy for the dance floor, Mum?”. She captioned the brief clip, “Crazy for the dance floor? #BirthdayWeekend #MomsInTown”.

Meanwhile, pal Hudson also used social media marketing to document the night’s celebrations, for example the moment when Bad blood singer was introduced for the stage to be with her unexpected appearance, singing an acoustic version of Shake It Off.

“This beauty gave just a little surprise for bday,” Kate captioned one Snapchat video.

“Happy birthday Reese, we like you!,” she added alongside another.

Reese, who wore a sparkly silver dress, also got in within the fun by hopping onstage to sign up country star Keith, who played guitar for just a rendition of Lynyrd Skynyrd’s Sweet Home Alabama, which featured around the soundtrack to her 2002 romantic comedy of the name.

“It would have been a great party,” the original source added. “When Reese left at 2am, she was at the best mood. You could tell she had the most effective time celebrating her birthday.”