You can now call Hailey Bieber "Auntie Hails."
As the model shared on Wednesday, Aug. 19, she is officially an aunt after her older sister, Alaia Baldwin, gave birth to a baby girl on Aug. 17.
"IRIS ELLE ARONOW!" the new mom announced on Instagram two days later. "Born on 8/17/2020, 6lbs 11oz. She is absolutely perfect, we are all happy and healthy."
Stephen Baldwin's firstborn also expressed her gratitude to her doctor, writing, "Thank you so much @drthaisaliabadi for making our experience go as smoothly and as beautifully as I ever could have imagined. We love you!"
As for Hailey, the proud aunt gushed to fans on her Instagram Story that it's "been hard to keep this to myself, my beautiful niece is here and she is PERFECT." She added, "Auntie Hails loves you sooooo much."
Baby Iris is the first grandchild for Stephen—and Alaia's first child with husband Andrew Aronow. The couple tied the knot in September 2017 with Hailey serving as her big sister's maid of honor.
Andrew also shared that he finally became a dad on his Instagram page. "Welcome to the world Iris Elle Aronow!" he wrote. "We couldn't be more thrilled to finally meet you Thank you so much Dr. A for helping her have such a smooth journey to us!!!"
The two announced they were expecting in April, just in time for the dad-to-be's birthday.
As their coordinating Instagram reveals read, "I made something extra special for @andrewaronow's birthday this year..... #BABYARONOW coming to ya August 2020...it'sagirl #happybirthday and #yourewelcome."
In response, Hailey had few words, but all the right ones. As she commented at the time, "Screaming!!!!"