"Yeah they know what they're having," she told Life & Style at the Angel Ball at Cipriani Wall Street in NYC on Oct. 17. "But I'm not telling!"
Although Tina kept mum on the gender of the baby, she did reveal that her daughter had morning sickness.
"She went through it, but she's got past it now," she tells Life & Style. "She's doing really good. She's busy."
"She's craving waffles," Tina says. "The normal - just wanting to eat!"
Tina, 57, couldn't stop smiling when asked how excited she was to be a grandmother for the second time.
"She's going to be an awesome mom," she tells as Life & Style. "I think it will slow her down somewhat, but I think she'll be the same great person she's been."
As for Jay-Z as a dad?
"I think he's going to be awesome," she adds. "They are very, very happy and just glowing. It's great to see."
Beyoncé and Jay-Z are expecting their first child together this February.
Photo Credit: Startraks