Theresa, the beautiful romantic has loved Ethan ever since childhood. She dreamt of marrying him and become "Mrs. Ethan Crane," and even planned their wedding! However, there was only one problemthey'd never even met!
Theresa was under a lot of pressure because her older brother Luis hated the Cranes. When Ethan and Theresa first met, Theresa spilled a can of blue paint all over him. After several accidents, Ethan became convinced that Theresa was stalking him.
However, Theresa secretly took a job at the Crane mansion. Ethan didn't know that his "stalker" was Pilar's daughter...he didn't even know her name! So when Theresa showed up for work, she had to wear a phony disguise.
After Theresa was exposed as Ethan's stalker, Theresa and Ethan grew closer, much to Gwen's chagrin. Ethan and Gwen have been together for several years, and have been pushed together by the Crane and Hotchkiss families. Ethan later discovered he had feelings for Theresa, after she confessed her love for him.
Theresa became manipulative and she began to lie (including having "Chuck" pose as her boyfriend, and locking Pilar in a janitor's closet at the Halloween dance!)
Ethan then cancelled his wedding to Gwen, and left a brokenhearted Gwen full of anger. However, Theresa had stumbled across some information...she learned that Ethan wasn't really a Crane! When this happened, she scanned the information into her computer after Rebecca and Gwen lied and tricked her into thinking that Ethan didn't want her.
After Rebecca and Gwen framed her for sending the information to the tabloid, Theresa went to Bermuda to talk to Julian. Julian raped her and married her, destroying Ethan and Theresa's relationship forever.
Despite her pleas, Ethan refuses to be with Theresa because he cannot trust her after she lied to him about his paternity, about marrying Julian, and about being pregnant with Julian's baby. After several lies, a desperate Theresa kept telling more and more to hold on to her man.
However, Theresa's love for Ethan was never doubted in his mind. Theresa had went to the execution chamber and down an elevator shaft just to save Ethan's life!
Now that Theresa has poured her heart out for Ethan, she promises never to lie to him again, and hopes that they will be together. Just before Ethan told her whom he had chosen (indirectly), Theresa told him that she hopes he will learn to trust her again, but if he wants to be with Gwen, she will not stand in his way again.