Kylie announced her pregnancy in September after rumours abounded for weeks prior.
She shared a video to Instagram about the journey so far, which included footage of her receiving a sonogram with Travis, with Stormi in attendance too.
It also saw Stormi hand the sonogram photos to her grandmother, Kris Jenner, who went on to say it was one of the happiest days of her life.
The video featured a lot of the Kardashian-Jenner clan, seen celebrating Kylie's 24th birthday, which took place in August.
The little bub is Kylie's second child with Travis, who is a rapper and record producer.
Their daughter, Stormi Webster, was born in 2018, with Kylie concealing her pregnancy right up until the birth.
The couple separated in 2019, but decided to isolate together during the first COVID-19 lockdown for Stormi's sake.
They rekindled their romance to become parents once more.
Kylie was honest about her hopes to have more children, and said so to Youtuber James Charles last year.
“I want more so bad, I actually think about it every day,” she said.
The new bub has been born into a big family full of ready-made cousins.
Her big sister Kim has four children, Kourtney has three, and Khloe and brother Rob both have one.
Kylie gained fame on Keeping Up With the Kardashians, but has since become an entrepreneur and business owner that has seen her gain notoriety on her own.
Congratulations to the once-again parents and new big sister Stormi!
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