Day made her debut versus in 1997. She was selected for the 2006 Six Nations Squad. She appeared again for the 2007 Six Nations opener. She can play on the wing, in the centre or at fullback. Sue played in three Rugby World Cups and is England's top try scorer with 61 tries in 59 caps. Sue or 'Daisy' as she is known to her team mates is the top try scorer in IRB world cups, with 19 tries. After retiring from 15's, Sue returned to the international game, captaining Simon Amor and Mike Friday's 7's squad to the 7's world cup in March 2009.