After playing for England U20s in 2017/18 and 2018/19, Galligan's full England debut came off the bench against
Ireland in the
2019 Six Nations. Her international career was interrupted by a bout of
meningitis in September 2019 followed by a serious injury in January 2020 when a fall in a line-out caused a broken leg and ankle along with three ruptured ligaments, so her second cap did not come until the
2022 Six Nations match against
Scotland. She was named in England's squad for the
Women's Six Nations Championship on 17 March 2025. She made the
Red Roses side for the
Women's Rugby World Cup in
England. == Club career ==