Kim Kardashian Celebrates Her Daughter's Birth on Social Media: '#momofthree'

Kim Kardashian West has returned to social media after announcing the arrival of her third child.

The Keeping Up with the Kardashians star, 37, tweeted a photo of herself on Tuesday evening, following her big baby news which she shared via her website earlier in the day.

Kardashian West – who wore husband Kanye West’s Yeezy line in the snap – celebrated her newest addition with the sweet hashtag, “#momofthree.”

The star also shared a photo of a pink cake decorated with pink flowers given to her by her mother, Kris Jenner, on her Instagram stories, with the caption, “Thank you mom.”

The new mom also added simple text to her Instagram stories, writing, “She’s Here!”

Kardashian West and husband Kanye, 40, welcomed their daughter on Monday, Jan. 15, at 12:47 a.m. She weighed 7 lbs., 6 oz.

“Kanye and I are happy to announce the arrival of our healthy, beautiful baby girl,” Kardashian West wrote in a post titled, “She’s Here!”

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She continued, “We are incredibly grateful to our surrogate who made our dreams come true with the greatest gift one could give and to our wonderful doctors and nurses for their special care.”

With the new baby on board, the West family is now made up of five members, including big sister North, 4½ and big brother Saint, 2.

And how do the siblings feel about their new sister?

“North and Saint are especially thrilled to welcome their baby sister,” the new mother said.

The Wests tied the knot in Florence, Italy, in May 2014, seven months after their engagement and almost a year after the arrival of daughter North. Kardashian West gave birth to son Saint in December 2015.

In June, a source confirmed to PEOPLE that the Keeping Up with the Kardashians star and West, 40, had hired a surrogate to help expand their family.

Multiple sources revealed to PEOPLE that the surrogate was pregnant in September, with Kardashian West confirming the news herself later that month.

Two days after news of the pregnancy broke, a source told PEOPLE the baby on the way would be another girl for the family — and that the spouses were “thrilled,” sharing, “They are so excited about their future baby girl.”

The new little girl is the first to arrive during a bit of a KarJenner baby boom. Kardashian West’s sisters Khloé Kardashian and Kylie Jenner are both expecting their first children in early 2018 — a girl for Jenner, 20, and a boy for Kardashian, 33.

But despite the closeness in their kids’ ages, there is no jealousy among the trio. As a source divulged to PEOPLE in October, “If there will be any friction at all, it’s that everyone is in each other’s business. But that’s like any close family.”

“There is no jealousy here,” added the close family insider. “No one is worried about anyone stealing their thunder. It’s not dramatic like that.”