Lux Cassidy is a fictional character and one of the protagonists of the CW television series Life Unexpected. She is portrayed by Britt Robertson. The result of a teenage pregnancy, her mother gave her up for adoption. However, she has a heart problem, meaning that she was never adopted and was entered into the foster care system, unknown to Cate who was told that her baby would be adopted. Lux was reunited with her birth parents whilst applying for emancipation.