Kristen Hallenga was born on November 11, 1985 in Norden, a small town in northern Germany, to a German father and an English mother, both teachers, according to the Times of London. When she was 9, she moved to Daventry, in central England, with her mother, Jane Hallenga; her twin sister, Maren Hallenga; and their older sister Maike Hallenga, all three survive her. Her father, Reiner Hallenga, died of a heart attack when she was 20 years old.

Ms Hallenga first felt a lump in 2009, when she was in Beijing working for a travel company and teaching. During a visit home to the Midlands, central England, Ms. Hallenga visited her internist. She told the Guardian that her doctor had attributed the lump to hormonal changes associated with her birth control pill.

But the lump became more painful and a bloody discharge developed. Another internist gave her a similar diagnosis to her first, again attributing her condition to hormones and the Pill. But because Ms. Hallenga didn’t know what would be considered normal, she had nothing to judge by.

“I didn’t touch my boobs at all,” Ms. Hallenga said in 2021. “I didn’t know anything about them.”

But Ms Hallenga’s mother, whose own mother had breast cancer at an early age, insisted her daughter be referred to a breast clinic. When she was diagnosed, eight months after finding the lump, her prognosis was terminal. The cancer had also spread to his spine.