Kotb sat down with ET at the Today show studios in New York City on Tuesday to talk about her new children's book, You Are My Happy, and she opened up about whether or not she and boyfriend Joel Schiffman are thinking about welcoming a sibling for their little girl.
"We don't know when, but it is something that is important to me and to Joel," Kotb shared. "We like the idea of Haley [having] a sibling because she has had such interesting circumstances to grow up."
"So it would be nice to be able to share it with somebody," she added.
Kotb says her latest children's book, You Are My Happy, was penned specifically for Haley, and she based the adorable illustrations, which included a lot of hugging teddy bears, on her daughter's own plush friend.
"She just got a kick out of the bears cuddling. She just thought it was cute because she has a bear she calls Brownie, because we're very original at our house," Kotb joked. "She always cuddles up with Brownie so I think she thought it was cute that the mother bear and the baby bear were cuddling together."
Kotb welcomed Haley -- her first daughter -- into her life when she was 52, and the host explained that motherhood was something she'd always wanted on a deep level.
"I always had this thing inside me like a voice that I couldn't quiet," she recalled. "It was a voice that [told me I] wanted to be a mom, but I thought it was too late."
"You can push a voice like that away for a long time but sooner or later it comes back up, and you have to address it," Kotb added. "I think the thing we all need to know [is] when your child arrives for you, that child is right on time. So your time may be when you are in your 30s or in your 40s or your 50s, but your child is right on time."
Kotb's heartwarming new children's book, You Are My Happy, is available for purchase now.