She received her Juris Doctor, magna cum laude, in 1990 from Pepperdine University School of Law.

[3][4][5] O'Connell worked at the law firm of Morrison & Foerster from 1990 to 1995, where she handled a variety of civil litigation matters.

[4][3] For five months in 2010 and 2011, she sat by designation on the California Court of Appeal for the Second Appellate District, Division 8.

She also served as Assistant Supervising Judge with the North Valley District of the Superior Court.

[4] On January 2, 2013, her nomination was returned to the President, due to the sine die adjournment of the Senate.