Her first professional singing engagements were with the Utah Symphony with Joseph Silverstein and with the Tabernacle Choir on their worldwide broadcast Music & the Spoken Word under the baton of Craig Jessop.

[17] She is recognized worldwide for her signature roles of Sophie in Der Rosenkavalier,[18] Gilda in Rigoletto,[19] Zerbinetta in Ariadne auf Naxos,[20] and Olympia in Les Contes d'Hoffmann.

[21] Morley's breakthrough career moment came when she stepped in at the last minute to sing Sophie in Der Rosenkavalier at the Metropolitan Opera during the 2013–2014 season, which was hailed as "a major success".

[24][25] In September 2018 she made her debut, while being 34 weeks pregnant, in Debussy's Le Martyre de saint Sébastien with the Deutsches Symphonie-Orchester Berlin.

She performed as Queen Marguerite in Les Huguenots at Bard College (2009),[29] Cunegonde in Candide at Los Angeles Opera (2018) [30] and in concert at Carnegie Hall (2018) [31] and with the Philadelphia Orchestra (2019).

Morley stars in the title role of The Metropolitan Opera's premiere of Matthew Aucoin’s Eurydice with libretto by Sarah Ruhl captured in the live recording.

(2018) [59] Additional recording collaborations include Princess Mi in Franz Lehár’s Das Land des Lächelns [60] with Christian Thielemann conducting the Staatskapelle Dresden for the 2019 Silvestergala, the Spanish lullaby A la Nanita Nana for the Christmas album Star of Wonder by Millennial Choirs & Orchestras (2020),[61] and Sophie in Strauss’s Der Rosenkvalier with Sebastian Weigle conducting, production by Robert Carsen alongside Renée Fleming, Elīna Garanča, Günther Groissböck, Markus Brück, & Matthew Polenzani (2017).

[62] Morley can be heard in excerpts from Handel’s Messiah with Tamara Mumford, Ben Bliss, and Tyler Simpson, the Mormon Tabernacle Choir and Orchestra at Temple Square.

Starring Laura Osnes and Martin Jarvis (2016),[63] and sings the role of Sylvie in this 2015 release of Gounod’s La Colombe on the Opera Rara label.

[64] She sings the title role in Mozart’s La finta giardiniera with Emmanuel Haïm conducting, production by David Lescot.