A Perth woman accused of stealing almost $140,000 from her Alzheimer's-affected mother spent thousands of dollars on event tickets, dinners at Crown and jewellery, the District Court in Perth has been told.

Key points: The woman moved her mother's money into her own account, the court heard

The woman moved her mother's money into her own account, the court heard Several years later there was little to show for the $270,000, the defence claims

Several years later there was little to show for the $270,000, the defence claims A family doctor told the court the woman was well cared for by her daughter

Siham Carollisen, 33, is on trial after pleading not guilty to stealing money from her mother on 10 occasions between July 2014 and June 2015.

State prosecutor Ryan Arndt said the money Ms Carollisen spent on herself was supposed to be reserved for her mother's living expenses.

"She treated it as if it were her own money," he said.

The court heard after Ms Carollisen's parents separated in 2012, her mother moved into the house where Ms Carollisen lived with her husband and child.

That same year, the 54-year-old woman was diagnosed with early-onset Alzheimer's.

As a result, Ms Carollisen was given powers to handle her mother's affairs during a Family Court settlement after her parents' divorce.

Charges ignore 'reality of complex family situation'

She transferred her mother's $270,000 share from the sale of the family home to an account in her name.

But this money was almost all gone by June 2015, when the Public Trustee was appointed to manage her estate.

Mr Arndt said there was "seemingly nothing to show for $270,000".

Ms Carollisen's mother moved in with her after separating from her husband. ( Facebook: Siham Carollisen )

Defence lawyer Mark Trowell told the court that they were "mean-spirited charges" which "ignored the reality of a complex family situation".

Not only was Ms Carollisen caring for a mother with Alzheimer's, she was also dealing with a husband who had a brain injury after a vehicle accident, he said.

He said Ms Carollisen looked after her mother and spent the money on her living expenses.

Mother was well cared for by daughter: Doctor

The trial also heard a statement from the family doctor who said Ms Carollisen's mother's condition had declined progressively since 2010, with symptoms including hallucinations, paranoia and an inability to converse in English, and that she was well cared for by her daughter.

It also heard from the Public Trustee, whose investigation into the disappearance of the proceeds of the sale of the family home led to the charges against Ms Carollisen.

A trust manager said when they first spoke to Ms Carollisen in 2016 about the money, she said it would "sound bad", but she needed to look after her family because she was five months pregnant, had no income, her then-husband had been in an accident and she was looking after her mother.

The trial has been set down for five days.