Sinead has a storied background in amateur boxing, competing in many matches on the highest level, domestically and abroad - on way to to 5 senior national titles ( in the highest division ) among other achievements. While boxing for Ireland in a team duel against England, in Dungarven, Waterford, kavanagh defeated the reigning British female middleweight champion in her first international level bout.Tony Davitt, one of the head coaches at acclaimed 'Drimnagh boxing club' asked her to join his club upon seeing her potential at this event.

Kavanagh then began training daily at Drimnnagh boxing club, a club which produced many great athletes including 1992 Olympic gold and 1989 world bronze medalist Michael Carruth.

After a mostly successful amateur boxing career kavanagh transitioned to MMA, training under John Kavanagh (no relation despite same surname) and his SBG Ireland team. She also regularly spars and trains with elite boxer and childhood friend Kellie Harrington.

Adding other skills to her already formidable boxing ability, she achieved a silver medal at the 'IMMAF world championships' in Las Vegas, 2015, before later turning pro.