Mary Adrienne Steckling Coen (she professionally used the name "Adri" without a surname) was born in 1934 in St. Joseph, Missouri. She began attending St. Joseph Junior College in 1953 where she studied retailing and design before moving to St. Louis to enroll in the School of Fine Arts at Washington University. Adri moved to New York City in 1955 after receiving an invitation to serve as a student guest editor for Mademoiselle magazine's 1955 college issue. She enrolled in the Fashion Design Department at Parsons School of Design, where she won a Mildrid Orrick Silver Thimble Award in 1957. While at Parsons, Adri completed an assisantship at Oleg Cassini, Inc. Throughout the 1980s and 1990s, Adri maintained her connection to Parsons by serving as a visiting critic. In 1991, Adri joined the Parsons School of Design faculty.

Adri worked as a design assistant for B.H. Wragge from 1960 until 1967. In the late 1960s, she founded Design Establishment with business partners Leonard Sunshine and Anne Fogarty. From 1968 until 1972, this venture formed the Clothes Circuit by Adri collection and Collector's Items by Adri divisons of Anne Fogarty, Inc. In 1975, she established Adri Clotheslab, Inc., a company through which she eventually licensed Habitat Industries to produce and market collections under her eponymous label. She changed the name of her business to Adri Studio, Ltd. in 1994. Her apparel was primarily sold through specialty stores or to private clients. Additionally, Adri maintained a licensing arrangement with Vogue Patterns. In the mid-1990s, Adri hired Benita A. Pullar, who worked under the name Brandy Alexander, as Vice President of Sales and Nadia Abdella as a business partner and manager.

As a designer, Adri often acknowledged the influence of fellow Parsons alumna and sportswear designer Claire McCardell. Adri's apparel was comfortable and often loose-fitting, allowing for ease of movement. She was known for oversized sweaters with wide arms, culottes, and neutral-vibrant pairings. Adri made extensive use of knitwear and often experimented with unusual, imported textiles. Her designs bear evidence of a "Bohemian" look, and, indeed, she often used her downtown Manhattan loft and its environs as a backdrop for fashion shoots. As described by Benita Pullar, "Her clothes were totally ageless, timeless and elegantly casual. The fabrics she used were mostly from the best Italian fabric producers, fabulously mated for each one of her seasonal collections...It was the beginning of a new and younger, timeless and modern, more casual manner of dress for women" (E-mail to the New School Archives, 11 May 2012).

Adri received the prestigious Coty American Fashion Critics "Winnie" award in 1982. Additional professional recognition included an invitation in 1986 to represent the United States for the Japanese newspaper Asahi Shimbun's "Best Five." Adri died in 2006. She was predeceased by her husband, children's book editor Fabio Coen, whom she married in 1982.