Trhesa grew up in Jackson, Mississippi, and graduated from St. Andrew's Episcopal School. In 1996, she received a Bachelor of Arts in English from the University of Virginia where she served as staff writer for the Cavalier Daily. After college, Trhesa worked as a history teacher at Oxford High School in Oxford Mississippi, and as a journalist at the Los Angeles Times. In 2007, Trhesa earned her Juris Doctor from the University of Mississippi School of Law where she served as executive editor of the Mississippi Law Journal. Trhesa has a state-wide family law practice, focusing in the areas of divorce, child custody, property division, taxation, pre- and post-nuptial agreements, adoption, fertility agreements and international abduction cases. Trhesa also serves as a certified Guardian ad litem in the Mississippi chancery courts and youth courts.

Trhesa is married to Eric Patterson, who grew up in Yazoo County, Mississippi. They were blessed with a son on May 13, 2009, and live in Ridgeland, Mississippi. Trhesa is often referred to as "Tresa", without the "h" - the result of a creative spelling back in 1975. Either way works just fine for her.