Born in Torphichen, Mallace played college soccer in the United States with the Milwaukee Panthers.
Torphichen is part of the (UK) Falkirk East and Linlithgow Constituency (Michael Connarty, Labour); Scottish Linlithgow Constituency (Fiona Hyslop, Scottish National Party); and part of the Armadale and Blackridge Ward of West Lothian Council (Stuart Borrowman, Independent; Jim Dixon, Labour; and Isabel Hutton, Scottish National Party).