Lewis, a qualified legal executive with no previous criminal history, silently cried during the reading of the summary of facts.
Justice Simon Moore told Lewis he was prepared to grant bail until her June 19 sentencing, but it was "almost inevitable" she would receive a term of imprisonment.
While working for a previous employer Lewis "developed bonds" with some of her clients, with several considering her to be a close friend.
When she left and set up her own companies, Lewis Administration Limited and Algin Trust Services Limited, several clients moved their trust administration and personal investments with her. All were elderly.
She acted as her clients' agent or as a trustee for her clients' trusts, thereby gaining complete control over their assets.
Serious Fraud Office director Julie Read said Lewis used that control to steal from her clients, in some instances using forged documents to commit the offences.
Between 2005 and 2011 she stole approximately $1 million in total, with one victim duped out of $193,669.
"Ms Lewis has committed a serious breach of trust against her clients, many of whom were vulnerable, elderly people with reduced capacity to manage their own affairs."
Of the money taken about $830,000 was used for Lewis' personal expenses.
Cash withdrawals of about $30,000 cannot be traced.
Justice Moore suppressed the identities of Lewis' victims.
What Lewis spent money on
• $336,000 to her overdraft account, including mortgage repayments, house renovations
• $214,000 to her personal account
• $62,000 to pay IRD debt
• $12,000 on vehicle expenses
• $11,250 on health and beauty products and services
• $5300 on food and entertainment
• $2700 on travel
