Born in Glasgow, McGuire was educated at the city's Our Lady and St Francis Secondary School (became part of St Mungo's Academy in 1988) on Charlotte Street and the University of Glasgow where she was awarded an MA in politics with history. She went on to study for teacher training at the Notre Dame College of Education (merged with Craiglockhart College in 1981 to become the St Andrew's College of Education, then became part of the Faculty of Education of the University of Glasgow in 1999) in Bearsden, gaining a Diploma in Secondary Education.