Known best as a performer and television writer for the E! comedy show Chelsea Lately, McDonald also contributed to the MTV program Lyricist Lounge. Also notable as an author, she published a 2010, New York Times bestselling memoir titled You'll Never Blue Ball in This Town Again: One Woman's Painfully Funny Quest to Give It Up.
After graduating from the University of Southern California, she trained at Los Angeles' famous improvisational comedy school The Groundlings and subsequently worked as a stand-up comic.
While building a career as a performer, she also earned a real-estate license.
She grew up in the Los Angeles area in a Catholic family of Irish and French-Canadian descent. Through her marriage to banker Peter Dobias, she has two children and one stepchild.