Kay was born in Queens, New York. Her parents, Luis and Imelda Trinidad, immigrated to America from Quezon City and Manila, Philippines, respectively. They met in New York on a blind date set up by their best friends. Kay is the middle child of 3 girls. Her sisters are Christine Trinidad Robertson and April Acosta.

Kay and her family moved from New York to San Jose, California, when she was three years old. She attended Los Alamitos Elementary School and made sure to perform in the talent show following in her older sister's (Christine), footsteps. Her performances ranged from self-choreographed dance routines to singing a cappella numbers, all performed with her best friends. She began taking piano lessons at the San Jose School of Music under Lee Reik and then Christopher Malloy. She also began voice lessons there around the age of eleven.

Upon entering sixth grade, she and her family then moved to Flower Mound, Texas. She attended Forestwood Middle School where she played volleyball, basketball, track and field, and soccer while also performing in choir under the direction of Lyn Zeller whom she is so grateful for. Mrs. Zeller gave Kay a strong singing foundation that she has since carried with her. She attended Edward S. Marcus High School while continuing to play volleyball, basketball and track and field until halfway through her junior year where she had to choose between sports and theater. Peg Waldschmidt began the musical theater division at the Texas high school and is a huge part of Kay's success, arming her with everything she needed to learn to get working in the real world. 

Kay went to New York University's Tisch School of the Arts. She attended the Lee Strasberg Institute for Theatre and Film. She left school a year and a half through when she was cast in the New York Premiere of BARE: A Pop Opera in the role of Diane Lee. She joined the Actors Equity Union with that production. She made her Broadway Debut as Aquata in Disney's The Little Mermaid.

Kay has been fortunate to work at numerous highly acclaimed regional theaters around the United States including Seattle's 5th Avenue Theatre, The MUNY, Musical Theatre Wichita, Cleveland Playhouse, The Cape Playhouse, Berkshire Theatre Group, Maltz Jupiter Theatre, The Old Globe (San Diego), Pasadena Playhouse, and Cleveland Playhouse. Some of her favorite roles include one of the Fates from Hadestown (Original Broadway Cast, Dir. Rachel Chavkin), Aquata from The Little Mermaid (Original Broadway Cast, Dir. Francesca Zambello),  Marcy Park from The 25th Annual Putnam County Spelling Bee (The Cape Playhouse, Dir. Jeffry Denman, Cleveland Playhouse, Dir. Marcia Milgrom Dodge), Tuptim from The King and I (Maltz Jupiter Theatre, Dir. Marcia Milgrom Dodge, Music Theatre Wichita, Dir. Mark Madama), Aysha from Children of Eden (concert at The Kennedy Center, Dir. Marcia Milgrom Dodge), along with making lifelong friendships in productions of Allegiance (The Old Globe, Dir. Stafford Arima)where she met and fell in love with the love of her life, Mike Karns, Waterfall (5th Avenue Theatre/Pasadena Playhouse, Dir. Dan Knechtges), and  Suessical (TheatreWorksUSA, Dir. & Choreo. Marcia Milgrom Dodge). She has performed at numerous venues around NYC including Joe's Pub, Les Poisson Rouge, The Laurie Beechman Theatre/Westbank Cafe, 54 Below, to name a few. 

Kay and her fellow sister Fates from Hadestown have a holiday album, "If The Fates Allow: A Hadestown Holiday Album," which will be released November 2, 2020, by Broadway Records.

You can purchase the album HERE!

Kay resides in Hamilton Heights in NYC with her loving and supportive rock star of a husband, Mike Karns, and their two pups Reno and Weezy. They faithfully attend The Journey Church NYC where they also participate in weekly growth groups led by Pastor Kerrick Thomas whose leadership and friendship they are so grateful for. All that is good comes from God. We love each other because he loved us first. (1 John 4:19)