She has a doctorate in Astrophysics from the University of Saint Andrews. Her thesis was on the pulsation of Delta Scuti stars. In 2004 Milligan co-authored the book "Chess for Children" with Grandmaster Murray Chandler.
She is an officer of the New Zealand Chess Federation.
She works as a coach at Murray Chandler"s National Chess Centre in Auckland. Milligan represented Scotland in eleven Women"s Chess Olympiads between 1982 and 2006.
Since 2008, she has been playing for New Zealand, as in 2007 she switched federations. She also competed in Women"s Zonal Chess Championships in Bath 1987, Blackpool 1990, Delden 1993, Saint Vincent 1999, and Gold Coast 2009.
Diane Savereide vs Helen Milligan, Thessaloniki Olympiad (women) 1988, Russian Game: Classical, (C42), 0-1
Helen Milligan vs Dana Reizniece, European Team Ch (women) 2001, Sicilian Defence: Old Sicilian, (B32), 1-0
Subbaraman Meenakshi vs Helen Milligan, Gibraltar Masters 2004, Queen"s Indian Defence, (E12), 0-1
Helen Milligan vs Anthony Ker, Queenstown Classic 2012, Pirc Defense: Classical Variation, (B08), 1-0.