Lemhagen was born in 1965 in Uppsala and went to Dramatiska Institutets director's program from 1988 to 1991. Her feature film debut was with Drömprinsen- filmen om Em in 1996.
Lemhagen's first full-length movie was Drömprinsen- filmen om Em which premiered in Swedish cinemas February 1996. It's about a young girl, Em, who one day sees her playhouse burn down. By accident her gaze meets the eyes of the one responsible for the fire whom she later runs into and a new, different friendship begins.
During the beginning of the 21st century came her big break as a film Director for films targeted at adults, not just adolescents. In 2008 she directed a movie called Patrik 1,5 which is about a gay couple who just moved to the suburbs where they bought a house. They are about to adopt a kid called Patrik who is one and half years old. Something goes wrong with the adoption agency and the kid they get to adopt is Patrik who is 15 years old and has a troubled background. It's about the struggle you face as a parent raising a troublesome teenager and their own struggle as a gay couple trying to live a “normal” life.
Her next planned movie is Pojken med guldbyxorna which will premiere in September 2014 on Swedish cinemas. It’s a remake of the book with the same title by Max Lundgren. It is about a boy who gets his hands on a pair of golden pants which gives him an unlimited amount of money.
