Katherine, the daughter of Birmingham Ornamental Iron Company founder Bert Meadow, was born at home at 1028 26th Street South, delivered by her grandfather. She attended Birmingham public schools and Fairfax Hall in Waynesboro, Virginia. She graduated from Birmingham-Southern College in 1941 with hopes of becoming a lawyer, but was discouraged by her family.
She married William Walter McTyeire and had five children. Seeing a need for a retail store to sell wrought iron furnishings, she borrowed $3,000 from her mother to open Iron Art on Southside in 1949. The business, which soon moved to Cahaba Road in Mountain Brook Village, flourished. The company was twice honored by the National Furniture Manufacturers Association. She was joined by her daughter, Kate McTyeire Millhouse and they ran the company together until deciding to close in 2007.
McTyeire was continuously active in civic work. She chaired the Alabama Sesquicentennial Committee in 1969 and joined the board of the Birmingham Area Chamber of Commerce in 1971. She also served on the boards of the Better Business Bureau of Alabama, Big B Drugs and First National Bank of Birmingham/AmSouth Bank.
McTyeire helped organize the Mountain Brook Merchants Association and served on the first board for the Emmet O'Neal Library. She served as a trustee of Birmingham-Southern College and as president of the its national alumni association. She was also an "Executive in Residence" at the Auburn University School of Business and helped create an advisory board for Auburn's interior design program. She also served as president of the Women's Committee of 100, the Junior League of Birmingham, and Mercy Home.