Rose to fame with her starring role as Lindsay Weir on Freaks and Geeks. She then went on to play Nurse Samantha Taggart on ER and Meg Rayburn on Bloodline. In 2015, she landed the role of Sarah in the movie Daddy's Home. She also voices the characters Wendy on Disney's Gravity Falls and Megan Sparkles on Nickelodeon's Sanjay and Craig.
She had her first acting role in the 1996 children's show Bone Chillers.
She had her first daughter, Lilah-Rose, with longtime boyfriend Steven Rodriguez in February 2012. The couple became engaged in 2013. She was previously in a five-year-long relationship with Jason Segel.
She acted alongside Freddie Prinze Jr. in the Scooby-Doo live-action films.