She may have been in hiding for the past several months as she enjoyed her pregnancy in private, but Kylie Jenner has been quietly racking up the dollar bills.

The 20-year-old reality star and cosmetics queen, who gave birth to her first child with Travis Scott on 1 February, has been declared the richest of all her siblings, according to MailOnline.

Despite her sisters including Kim and Khloe Kardashian having a pop at beauty lines, Jenner is sitting on top of a globally successful beauty empire and has been declared the sibling with the most.

Her company – Kylie Cosmetics – began as a hobby for the star, with 5,000 branded Lip Kits created for sale, and is now valued at $386m (£277m). It is projected to be worth $1bn by the year 2022.

Jenner's older half-sister Kim, 37 – who is worth approximately $175m – recently earned $10m in just four days according to TMZ. Her new fragrance line, Kimoji Hearts, sold out recently, with the star saving a lot of money by using social media for the whole advertising campaign.

According to Forbes Khloe, 33, is the next richest sibling with $40m to her name, followed by eldest sister Kourtney with $35m. Rising model Kendall Jenner has $18m while brother Rob has approximately $6m.

Jenner may have revealed the secret to her success in a candid chat with her mother Kris Jenner for LOVE magazine, where she claims that she didn't create her brand "to make money".

Explaining her success, she said: "I think truly, I put a lot of hard work into this.

"It's not like I'm doing this to make money. I don't even think about that part. This is just something authentic to me."

And the new mother is after world domination when it comes to her brand, with her mum shooting down speculation about her daughter selling the company.

The momager said: "I don't think she sees herself stepping away from this brand for many years.

"There is so much more to do with the brand. There are so many pieces of the puzzle to put together to create an entire line of cosmetics. The goal in the future is to just build the whole infrastructure, and figure out what a retail model might look like that could take it globally."