Ninfa Rodriguez, a Mexican American Catholic, was born on May 11, 1924 in Harlingen, Texas. Rodriguez, one of twelve brothers and sisters, was raised in Harlingen. She graduated from Henrietta M. King High School in Kingsville and Durhan Business School in Harlingen. Rodriguez's father grew crops in a patch of farmland in the Rio Grande Valley.
In 1945 she visited her twin sister, Pilar Di Meo, in Providence, Rhode Island. During her visit, she met Domenic Thomas Laurenzo, a graduate of the Massachusetts Institute of Technology. Laurenzo, a native of Rhode Island, was of Italian descent. Rodriguez, who had nicknamed Domenic Laurenzo "D.T.," married him. In 1947 their first child, Roland, was born. The couple considered whether to move to Houston or Los Angeles. They read a 1948 newspaper article that stated that Houston was the fastest growing city in the United States. Tony Mandola, Ninfa Laurenzo's son in law and a member of the Mandola restaurant family, said that they decided to go to Houston after flipping a coin.
In 1949, they opened the Rio Grande Tortilla Company factory, which sold pizza dough and tortillas. The couple entered the business even though both of them had professional degrees. The factory was located in a Hispanic community in the East End. The Laurenzos lived in a wooden frame house next to the factory. The couple had four more children, with Jack born in 1949, Phyllis born in 1953, Tom born in 1958, and Gino born in 1963. The family sent the children to an area parochial private school.
Ninfa Laurenzo's factory was in trouble due to increased competition and decreased profit margins. In 1973 Laurenzo opened a 10 table restaurant in front of her tortilla factory in order to financially stay afloat. The restaurant, Ninfa's, became very popular and it became her core business. She did not have prior restaurant management experience. While at the restaurant, Laurenzo greeted guests, watched over the kitchen operations, and sometimes sang songs in an alto voice. Joe Pratt, a professor of business and history of the University of Houston, said "In the 1980s, Ninfa became a symbol of the city's growing diversity and the opportunity for people who hadn't always had opportunities here. She is a powerful image in Houston."