Armstrong married Irish fencer, Patrick Joseph Duffy who founded The Irish Academy of Arms (Academie d'Armes d'Irlande) in 1952 as well as the highly successful club - Salle Duffy. They helped to build it into a club which dominated fencing in Ireland and became one of the premier clubs in the country. In 1958, they were both heavily involved in the re-establishment of the International Academy of Fencing Masters. Both coached in the fencing clubs at University College Dublin, Royal College of Surgeons and Trinity College Dublin.[3] as well as St Conleth's College, St Killian's School, Wesley College, Sandford Park School, Sutton Park School, St Gerard's School and many other schools in Dublin.[4][5]
For the 1960 Summer Olympics, Armstrong was one of only two women selected to represent Ireland; the second was Maeve Kyle.[6] Armstrong won one bout in the women's individual foil, attaining fifth position in her round 1 pool.[2]
Armstrong died on 21 December 2018, in Roscommon University Hospital.[7]
