McGuinness started competing in
swimming, having been inspired by the
2012 Paralympic Games in London. She was encouraged by
Ellie Simmonds to attend the
World Dwarf Games. McGuinness took up
Paralympic powerlifting in 2019; initially, she could lift . In 2023, McGuinness won a silver medal at the World Cup. That year, McGuinness competed at the
2023 World Para Powerlifting Championships, Following the event, she qualified for the under-55kg event at the
2024 Summer Paralympics. In July 2025, McGuinness broke the British under-61kg record twice at the Irish Invitational Para Powerlifting Competition. Her best lift was . That month, she finished second at the British Championships behind
Olivia Broome, with a best lift of . She was selected to compete at the 2025
World Para Powerlifting Championships, where she was 10th in the under-55kg event with a best lift of . ==Personal life==