The ex-politician, 37, is accused of embezzling more than £40,000, the majority of which from the Women for Independence campaign she co-founded in 2012.
She faces three counts of embezzlement, as well as a charge relating to her alleged failure to disclose a password for an iPhone to police.
The trial had been expected to begin today but was delayed until later in the week.
Ms McGarry, from Clarkston, dramatically sacked her previous defence counsel just days before the trial had been due to start.
Court proceedings are expected to last for around six weeks.