"This didn't just fall into her lap," she told HELLO! on the pink carpet ahead of the show on Tuesday night. "She's missed it twice. This was her third try and she pulled it off and got a spot that millions of beautiful, beautiful women deserve as much as she does but that's a part of the game."
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Gigi and Yolanda attended the Victoria's Secret show afterparty together
On hearing the news that Gigi had won a spot on the runway, Yolanda said that she "started crying".
"She called me the minute she walked out from the car and it was probably one of the highlights of a mother's life," she said.
"I've watched the video a hundred times and I keep crying every time I see it because her reaction was just so sweet!"
Gigi wore two outfits on the runway
Yolanda added that she had brought a tissue with her because she was "probably" going to cry when she saw Gigi walk.
Gigi is bound to have made her mother proud as she strutted the catwalk in a stunning butterfly-inspired ensemble.
The blonde beauty shared a picture of herself posing with best friend Kendall Jenner backstage.
The model looked right at home on the catwalk
"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 @victoriassecret @ed_razek #vsfashionshow2015," she wrote alongside the snap.