Ysgol Trelaw was officially opened on March 6, with 30 pupils. It was particularly special to Anne-Marie because she had met her future husband while working in the Welsh settlement in Argentina.
She was homesick when she first arrived at the former colony in 2001 but soon fell in love with the people, country and her new love Fabio Lewis.
Building a new school was estimated at 125,000 pesos (pound;26,000).
Anne-Marie, who now lives in Pontliw, Swansea, said: "I realised a permanent centre for the language was a necessity if Welsh was to survive in the town.
"It was always my dream to go to Patagonia. It was a once-in-a-lifetime experience for me to be chosen and to teach Welsh so far from home."
Anne-Marie soon settled into the more relaxed pace of life. "I'd often walk home from classes singing."
The Cymdeithas Cymru-ArianninWales Argentina Society started fundraising events for the new school more than two years ago. A cheque for pound;30,000 was finally handed over to the Trelew Welsh Society at its annual Eisteddfod last October. Anne-Marie married Fabio back home in Wales in 2003.
She now organises holiday tours for groups from Wales to Patagonia and Argentina and still teaches.
* The first Welsh settlers to Patagonia went in search of a better life.
* They paid pound;48 to sail on the Mimosa in 1865, arrmed only with their beds and cooking utensils.
* The ship docked at Golfo Nuevo on July 28, 1865. The settlers started out as agriculturalists in the fertile Chabut province.
* Both the Argentine and British governments helped the colony through hard times and successive droughts.