SAN FRANCISCO (KGO) -- If you ask Shauna Harrison how many brothers and sisters she has, she may not be able to answer.
"People will ask, 'Oh, so, do you have siblings?' And I am like, uh, no. Yeah. Umm, yes. About 29 of them!"
At age 27, Harrison learned that her dad wasn't her biological father. Harrison, who grew up in the Bay Area as a single child, set out seeking answers, mainly to learn about her health history.
"I had been asking questions about my health and blood type," explains Harrison, a fitness professional with a Ph.D. in public health. "Because of my background in public health, I wanted to find out if I am more susceptible to certain things. I lead a pretty healthy lifestyle as it is, but I just want to know."
She tried the ancestry site 23andMe, and found out that the donor, who lived in the Bay Area, was Jewish and of Russian descent.
Harrison says after that discovery, she stopped searching. But then in 2017, she went back to the site after learning about some advancements to DNA science and the website.
"Boom! Next day I get an email from one of the siblings. 'Looks like we are related. Not sure if that's a surprise to you,'" says Harrison.
Yet the bigger surprise was there was a total of eight others. It's been two-and-a-half years since, and the family keeps growing.
"Just about a month ago, there were three (new siblings) within two weeks," she says.
That brings the total to 30 children, who range in age from 41 to 24. Shauna is the third oldest.
"Two of us are born two-and-a-half weeks apart. And the other two are born two days apart. So, things like that are a little weird to me. Are we from the same sample? Are we almost twins? I don't know! How does that work?"
"Turns out I was number 15," says Jodi Hale.
Hale says she, too, tried 23andMe in search of answers, but sensed that she may have had a different father when she was a teenager.
"Both of my parents have blues eyes. I do not."
Hale met Harrison for the first time two years ago at a Starbucks in Sunnyvale. Hale says there was an instant connection.
"It's just nice to have someone else that is in sort of the same place. And you have a lot of the same history. It's fun," says Hale, who works in software sales.
While these two sisters have developed a strong bond and welcome this whole experience, they admit it has been overwhelming and full of challenges.
Some of the siblings only learned that they had a different biological father after they got the results. Some have chosen to remain anonymous.
Harrison says several of her half-siblings have met, or are at least in contact, with the biological donor, who they were able to track down. She says the donor wanted to father a lot of children.
Hale and Harrison say there is a private Facebook page used by the siblings, a spreadsheet to keep track of birthdays and a welcome packet for new family members.
"It's just non-stop. I don't think this is going to be it. I think it's just going to continually happen, probably for the rest of my life," says Harrison.
She adds, if a new one does show up, they say they're ready to welcome them to the family.
2 Bay Area women linked to 28 siblings following DNA test