The 37-year-old actress, who announced her pregnancy in June, revealed that she's craving "mostly sweets" despite usually not really caring for them, adding, "I wake up every morning really wanting a donut... or ten."
Two benefactors of the newfound sweet-tooth are Heigl's daughters -- Nancy, 7, and Adalaide, 4 -- who the actress shared an adorable photo of last week, with the caption, "Way to my girls hearts! Family ice cream night!"
"They're so excited," Heigl told ET of how her daughters are feeling about getting a baby brother. "For them, it's an 'out of sight, out of mind' thing. They'll forget about it for a while, and then suddenly be like, 'Hey have you had that baby yet?'"
Heigl revealed at the Doubt TCA panel the family is headed to their home in Utah for the holidays this year, right before they are expecting their baby boy -- which Heigl said her husband, country singer Josh Kelley, is particularly excited about!
"Josh is hugely ready [to have a boy]," she said. "He’s just surrounded by women! It’s me, the two girls, my niece Madison often lives with us in Utah... and then my mom."
"His brother had a baby last February, a little boy named Ward," she added, noting that the Kelleys brothers are already excited to play golf with their little ones, saying, "They're already talking about their foursome."
Meanwhile, Heigl's upcoming legal drama, Doubt is coming to CBS this fall. The actress told ET that her role on the show feels like "a combination of a lot of different characters" she's played in the past, only with a little more perspective.
"It's been really fun to play her because she does, on some level, feel familiar," she explained. "But -- because of age and experience -- there's a level of intelligence and sophistication to her that I haven't always gotten to play."
At the panel, Heigl also complimented her former Knocked Up co-star, Seth Rogen, who recently opened up about feeling "betrayed" by past remarks she'd made, calling the 2007 film "a little bit sexist."
"I respect the fact that maybe she realizes it has hurt her career,” Rogen said on Howard Stern's Sirius XM radio show, adding that Heigl hadn’t apologized to him or Apatow for what was said. "I don’t want that to have happened to her at all because I’ve said a thousand stupid things, and I really like her."
"I think that he’s handled that so beautifully and I just feel nothing but love and respect," Heigl told reporters, when asked about his comments. "It’s so long ago at this point, I just wish him so much goodness and I felt that from him too."