She is played by Courtney Henggeler.
She is stern, but also loving and supportive of her family, though she can sometimes butt heads with Daniel's mother, Lucille. She is also Daniel's business partner at LaRusso Auto Group.
Amanda is the constant voice of reason in the series. She is a very wise, grounded, and practical person, and can de-escalate conflicts with a few well-chosen words. Little is known about Amanda's background. It's possible that her parents are either dead or live far away, as when Amanda tells Aisha that Sam is with her grandmother, Daniel immediately knows she is referring to his mother.
It is also not known how long she and Daniel have been married. Prior to opening LaRusso Auto Group in 2002, she and Daniel had already worked in auto sales together as "Danny and Mandy, the best sales team in the Valley". It is likely that the two have been married since about 2000.