Gigi Hadid
As a model, Gigi Hadid is used to pouting but she has jumped on the 'fish gape' bandwagon. Jason Merritt/Getty Images

Celebrations are in order model Gigi Hadid, who marks her 21st birthday on 23 April, 2016. To mark her big day, IBTimes UK recaps some of her biggest highlights from the last 12 months.

Zayn Malik romance

In December 2015, the rumour mill went into overdrive after Hadid was pictured leaving Justin Bieber's post-AMAs party at The Nice Guy in Hollywood, along with former One Direction star Zayn Malik. Days later the pair, who were both free and single after ending their respective relationships, went public by holding hands in public for the first time. Five months on and they are said to be talking marriage.

"They were seated at a private table tucked away in the back [of Butter restaurant]," a source told Star magazine (via HollywoodLife). "Honestly, it didn't look like anything special was going on, that is, until Gigi practically jumped out of her seat and yelled, 'Yes!' They even got a round of applause from some other diners!"

Gigi Hadid
Gigi in arms of her boyfriend, Zayn Malik. Gigi Hadid/Instagram

Victoria's Secret debut

In November 2015, the young model got her wings and donned tiny lingerie to become a Victoria's Secret Angel. She made a dramatic entrance at the lingerie giant's annual fashion show in a revealing teal number, before changing into baggy yellow trousers and a tiny red crop top.

Ahead of the show, she tweeted a behind-the-scenes photo of herself with BFF Kendall Jenner, sporting the caption: "No one I would have rather shared my VS v-card with ;) This show is genuinely a dream come true. Can't thank you enough."

Victoria's Secret fashion show 2015
Gigi Hadid presents a creation during the 2015 Victoria's Secret Fashion Show. Lucas Jackson/Reuters

French Vogue cover

Earlier this year, Hadid stripped off for the cover of Vogue Paris. In the racy black-and-white shoo - the work of duo Mert Alas and Marcus Piggott - she posed on wooden blocks, wearing nothing more than a pair of pearl-detailed stiletto Chanel mules and oversized cuffs. She placed one arm across her chest and crossed her legs to protect her modesty. The accompanying title read: "The phenomenal body with 10 million fans".

Video vixen

Days after going public about her romance with former One Direction star Zayn Malik, Hadid confirmed that their relationship was already pretty serious, by appearing as the love interest in the music video for his début solo single Pillow Talk, which premiered on 29 January 2016. Throughout the five minute visuals, the pair share steamy kisses and passionate embraces.

New face of Topshop

In June 2015 the rising star was unveiled as the new face of popular high-street brand Topshop. For the campaign - shot by Tyrone Lebon and styled by Topshop creative director Kate Phelan - she channelled a range of looks for the labels, sportswear, work and evening ranges.

Announcing her new role, Topshop boss Sir Philip Green said that the beauty was the ideal ambassador to take the brand forward: "Working with Gigi Hadid on this campaign continues to strengthen our international vision for the Topshop brand. We are continually developing our footprint across all markets with ambitious plans both in the UK and internationally and I feel like Gigi is an ideal ambassador to underpin these efforts."