The 25-year-old model has heaped praise on Dua - who turned 25 on Saturday (22.08.20) - on her Instagram Story, calling the chart-topping star her ''sister''.
Dua is dating Gigi's brother Anwar Hadid and the loved-up couple have a puppy together called Dexter.
In her post, Gigi wrote: ''HAPPY BDAY DEXTER'S MOM @dualipa.
''You're a special one & deserve the best. love u sister (sic)''
Bella Hadid also posted a birthday message to Dua on social media.
The 23-year-old model called the London-born star the ''cutest, smartest, most hard working, loving, generous bean of all time'' on her Instagram Story.
She added: ''You are sweet as pie ... a blessing to our fam and the world Love u sister (sic)''
Meanwhile, Dua recently moved to Los Angeles in order to be with her boyfriend.
The 'Break My Heart' singer is living close to Anwar's family in Beverly Hills after the pair spent lockdown together in London, and they reportedly ''see their future in LA''.
A source recently said: ''It was difficult to get to the US in the first place and she knows it's not going to be easy going back and forth because she would have to quarantine for weeks on end. It's tough, because all of her family and a lot of her friends are in London.
''But she knows plenty of people in Los Angeles, as does Anwar, who has lived there in the past, so she's feeling optimistic. Being in the US right now is great for pushing her career there too, especially with new music coming out.
''Dua's making their new place nice and homely and she has just got a puppy called Dexter with Anwar because they see their future in LA.''
Former Bengal Lancer Harry Sullivan, aka From The Tiger's Mouth, has just released his first solo single - 'Morning News' under his new moniker.