In "Stranger Things," Terry Ives gave her daughter the birth name Jane. The child was taken from Terry soon after birth and later became known publicly as Eleven, the number assigned to her at Hawkins National Laboratory.
Terry had participated in experiments connected to Dr. Martin Brenner while unknowingly pregnant. Brenner’s laboratory separated Jane from her mother and concealed the kidnapping by making Terry believe—and telling others—that she had suffered a miscarriage. Terry never accepted that explanation and eventually tried to recover her daughter.
Jane’s identity is gradually revealed through the series, especially when Eleven visits her mother and experiences memories of the laboratory. The name Eleven refers to her test-subject identification, not her original identity. After Hopper becomes her legal guardian, she is also known as Jane Hopper, which can cause confusion in quizzes asking specifically for her birth name.
Kali Prasad, known as Eight, is another former Hawkins Lab subject and is sometimes described as Eleven’s “sister,” but Kali is not Jane’s birth name or biological sibling.