The 32-year-old singer, a finalist on the seventh season of the hit U.S. talent show, and her husband, David Ray, will welcome a baby brother for three-year-old daughter London in late summer (16).
"Meet our handsome little dude, due Sept. 2nd!" she wrote beside an Instagram photo of her ultrasound.
Brooke goes on to reveal conceiving wasn't easy as the couple had to undergo in vitro fertilisation (IVF) to become parents again.
"It's hard to believe it's even real...," she continued, "Cause, WHEW, It's been a process. infertility is hard. IVF is downright crazy, I've been a hormonal mess for several months, but it's totally worth it, because it finally worked. Hallelujah!"
"Yes! We are so happy, we are so thankful," she added. "Yes, I have a million thoughts and feelings about this journey, cause my heart is humbled and very tender for this struggle and the many women I've come to know through it....12 weeks down, 28 to go!"