Olsen and husband Louis Eisner welcomed a son, Otto, earlier this year.
The Full House cast was thrilled to hear that their house just got a little fuller!
On Monday's episode of How Rude, Tanneritos!, a Full House recap podcast hosted by series stars Jodie Sweetin and Andrea Barber, the pair took some time to send well wishes to their former co-star, Ashley Olsen, who has welcomed her first child with husband Louis Eisner.
"I just heard this this morning, that Ashley Olsen had a baby! That blows my mind," Barber said as the pair discussed a scene featuring baby Michelle Tanner, who was played by both Ashley and her twin sister, Mary-Kate, when they were toddlers.
"The baby had a baby!" Sweetin confirmed with a laugh. "I'm sorry, I know she's not a baby. She's a 37-year-old woman, I realize that. But it's like when the youngest member of your family has a kid. It's like, 'Ah, it's happening!'"
Sweetin, who played Michelle's older sister, Stephanie Tanner, on the beloved sitcom, noted of Olsen and her husband, "I'm sure they'll keep it private for sure, as they do, but I want to wish them well and congratulations! Welcome to motherhood!"
"The Full House family is so happy for them," Barber added.
Olsen's happy news became public earlier this week, when a source confirmed to ET that Olsen had given birth to a baby boy, whom the couple named Otto, earlier this summer. The actress-turned-fashion designer kept her pregnancy under wraps, with few knowing that she was even expecting.
According to a source, even some of Ashley's friends were out of the loop. "She kept her pregnancy secret from a lot of friends and colleagues," the source said. "Only a small circle knew."
As for how she pulled it off, the source said that the new mom's signature oversized outfits helped, as did the fact that the couple has been spending a lot of time in the Hamptons.
Of course, some important people who did know about the pregnancy were her family, including, of course, Mary-Kate. They are all "beyond excited to have a new addition to the family," the source noted.