Lena was the illegitimate daughter of Christian Henrike Kunibert Schneider and Magdalene Hildegarde Becker. She was most likely born in Drolshagen, North Rhine-Westphalia, Germany. It is known her father did not know of her existence until Lena reached the age of nine months. And wasn't able to see his daughter for the first time until after she reached her first birthday.
According to several existing photographs, she and her father had a good father-daughter relationship, Christian having described her and Magdalene as "the little stars in his life."
Lena Schneider most likely had a good mother-daughter relationship with Magdalene, for she spent a large amount of her childhood with her.
After finding out her father was killed by the beginning of World War ll, Lena was devastated, and determined to see his body. Not long after the death, Magdalene abandoned her daughter, distraught.
This lead the sad stricken Lena to run away from the shackles of her upbringing, and to run to Berlin. There, she was brought face-to-face with her deceased parents; both of which were infected by the zombie virus, and became unmentionables. Devastated at hearing that this meant her parents were gone, Lena purposefully got bitten by a zombie (most likely her father himself as a zombie), and succumbed to the infection. Her status is zombified.