The supermodel turns 24 on Tuesday (23.04.19) but kicked off the celebrations on at L'Avenue at Saks in New York City on Monday night (22.04.19), where she was joined by a host of famous guests that also included Martha Hunt, Olivia Culpo, Marc Jacobs, Ashley Graham, Justin Ervin, Hailee Steinfeld, Laura Polko, Patrick Ta and Samuel Krost.
An insider told E! News that the sisters were the ''life of the party'' and spent the evening dancing with their mum Yolanda and celebrity friends to R&B.
The source said: ''Gigi and Bella were the life of the party. They were having a great time and everyone was taking photos of them. They then pulled Yolanda to dance with them and were dancing with their mom. It was a really cute moment.
''At one point, everyone was dancing together circling around Gigi in the restaurant as the DJ was blaring music. Gigi and Bella were dancing to Drake and Rihanna most of the night and were having a blast together. They were both smiling and taking photos together on their phones.''
The source also explained that Gigi was ''super excited'' to see the 'Ready For It' hitmaker, while the pop sensation looked ''really happy'' to be out with her pals.
''Taylor looked really happy. She was very relaxed but looked happy to be there. She was bopping her head to the music, dancing a bit. Gigi was super excited to see Taylor and they gave each other a huge long hug.''
The insider added that Gigi's parents brought out a cake in the shape of a '24' and the whole group sang happy birthday to her.
They said: ''Everyone was drinking champagne and tequila and cheersed Gigi with birthday shots after she blew out her candles on the cake. Gigi had a huge smile on her face and looked so excited to be celebrating.''
What's new in the music world this week?
'Sounds of Silence' was released on this day (January 17th) in 1966.
Listen to Alex Bayly performing 'Animal'.
Two weeks ahead of Independent Venue Week, Dry Cleaning made 'Britain's Best Small Venue 2015' (NME) the second port of call on their 2020 tour.
'Leave Home' was released on this day (January 10th) in 1977.
For their last gig of the year, The Libertines came back to their adopted hometown of Margate to finish off their latest tour.
Celebrating the birthday of David Bowie with his most legendary songs.