Career
She is the younger sister of Irish marathoner Regina Joyce. Both sisters represented Ireland in the 1984 Summer Olympics, Regina in the Marathon and Monica in the 3000 meters. Previous to the Olympics Monica had represented Ireland at the 1982 European Athletics Championships, the 1983 World Championship and the 1984 World Cross Country Championships.
She also ran in the 1985 World Cross Country Championships, finishing 12th and the IAAF World Women"s Road Race Championships finishing 8th.
She was winning cross country races as early as age 11. Before embarking on her international career, she competed for San Diego State University for two and a half years, finishing second in the 1500 metres at the National Collegiate Athletic Association Women"s Outdoor Track and Field Championships in 1981.
She became a United States. citizen in 2000. At age 50, she beat the W50 World Record in the 5,000 meters at the Mountain.
SAC Relays, running 16:19.51.
That year she also added the 15K road running W50 world record, running 52:38 at the Gate River Run. She also added American records in the 5K, 8K and 10K, the latter for a second time with a 30-second improvement.