The Kardashian-Jenner clan just got bigger!
A source tells ET that the reality star "is doing well and is happy."
"Kylie always wanted to be a young mom," the source says. "She may be young, but she's very maternal and has lots of practice with babies! She's a very hands-on aunt and was basically a step-mom to Tyga's kid."
The "baby will be very well cared for and so loved," the source adds. "Kylie is excited that her baby will have cousins close to her age too!"
Jenner has previously talked about wanting to have children at a young age.
Last April, a then 17-year-old Kylie said she hopes to be a mom by 27. "When I look to the far future and decide to have kids, I need to have a million girls," she told Teen Vogue. "Ten years from now -- in 2025 -- I hope I have a kid."
Meanwhile, in an interview with ELLE UK in 2015, Jenner revealed how motherhood would have an effect on her social media.
"Once I have a kid I'm not going to be on Instagram," she explained. "You know, I'll probably delete my Instagram and just… I don't know, live life."
"I would love to have a family and build a home with a farm in Malibu Canyon and just have my kids and throw away my phone, and just really, like, live my life and not do this anymore," she added.
For more on that interview, watch below: