Marie Osmond announced on "The Talk" on Monday that her son and daughter-in-law are expecting a child. But she started her announcement with a joke that shocked the audience.

"I'm pregnant!" the guest co-host declared as the studio audience erupted in cheers, causing her to laugh and then shout, "No! No! But my daughter-in-law is!"

Osmond, 53, was a singer, actress, and "Dancing with the Star" contestant. On "The Talk," she explained that her son Stephen Craig and daughter-in-law Claire Olds are expecting a child, Us Weekly reports. Craig and Olds married in 2011. Osmond could barely contain her excitement about becoming a grandmother for the first time.

"I am so excited I'm going to be a grandma," she told the other ladies and hosts on the show. "I just can't wait. We went in for my son -- for his birthday -- he turned 30, which is amazing 'cause I'm 29."

"He blew out the candles and then blew me away and said, 'You're gonna be a grandma!'" she continued. "It was really fun."

Sharon Osbourne, also a recent grandmother and co-host of "The Talk," congratulated Osmond on her new role

"It is the best ... It's a gift from God! Congratulations," Osbourne said.

Osbourne's son Jack and daughter-in-law Lisa welcomed daughter Pearl in April 2012.

In other Marie Osmond news, on Tuesday a giant prop spider was used to scare the guest host on "The Talk," Starpulse.com reports.

Osmond was explaining her fear of spiders to the audience.

"I hate spiders... My mother used to make us put up clothes on a clothesline and it was cold out so I went to put on a sweater and as I went to put my hand in (to the sleeve) it was like this bag of spiders (all over my arm)..." Osmond said.

The star didn't get to finish her story as a fake spider was placed on her shoulder, causing her to scream and jump out of her seat, shouting, "Jeez! It's not even funny!"

Co-hosts Aisha Tyler, Sharon Osbourne, Sheryl Underwood and Sara Gilbert laughed, while Osmond continued to yell: "Ah! Get it away!"