They were all donor-conceived siblings, each with a different mother but the same donor as the father.
ELLICOTT CITY, Md. (KABC) -- A young woman in Maryland unlocked lifelong questions during her search for her family members and with the help of a genetics service, she's now a part of a true "modern family."
Brenna Siperko recently discovered she has at least 60 siblings she never knew she had. They were all donor-conceived siblings, each with a different mother but the same donor as the father.
After she turned 19 last year, Siperko submitted her DNA to a genetics service, which told her she had 13 siblings. That number grew even higher in recent weeks.
"Up to 60," she told WJZ-TV. "Who knows how many more there are."
The group of siblings are close in age, ranging from 14 to 27 years old. They reside across Canada and the U.S., including California. Siperko said the discovery has been a bit overwhelming.
"It's a lot to process," she said. "At first, I was, like, stunned by it."
Wendy Kramer, who runs the Donor Sibling Registry, told WJZ-TV the largest known sibling group consists of 240 people.
CNN contributed to this report.