The New York Post's Page Six was the first to report on Trump's baby news on Thursday, April 11. She later tweeted, "Jared and I and are so excited that Arabella will become a big sister this fall. Thanks for all your good wishes!"
The Celebrity Apprentice mentor, 31, is already mom to daughter Arabella Rose, almost 2, with Kushner, who's the chairman of Observer Media Group.
Last month, Trump, who works as the Executive Vice President of Development & Acquisitions at father Donald Trump's Trump Corporation, opened up to Us about the challenges of balancing work and family.
"I want to make sure I'm with my daughter when she needs me to be with her, but I also know that it's okay to go to the office when I'm working on a big deal then I'll make [family time] up on the weekend," she explained. "I try to think of parenthood as a marathon, not a sprint. I know that I have to do well at this by taking it one day at a time and not beating myself up too much over small things."
Married to Kushner since 2009, Trump also spoke to Us about her plans to expand their family. "I just haven't decided when [we'll have another baby] yet, but at some point," she hinted. "That's the plan."