Mildred Mawarire had pleaded not guilty at Warwick Crown Court to a number of charges relating to cheques which had been withdrawn from her victim’s account.
But on the day she was to stand trial, the 27-year-old, of Mellowdew Road, Stoke, admitted eight charges of procuring the execution of valuable securities by deception.
She had conned pensioner Florence Humphreys to write out cheques on the basis the money was to pay for care, then altered the amounts before paying the cheques into her own account.
Mawarire, who was working at a care home in Rugby, fleeced the vulnerable old lady out of of more than £16,000.
Also due to stand trial was her husband Entheny Mawarire. But the 42-year-old pleaded guilty to one charge of receiving a stolen debit card and three charges of using it to obtain goods by deception.
The court heart Mildred Mawarire entered her guilty pleas on the basis she had befriended her victim and had discussed her family in Zimbabwe, as a result of which the old lady had given her what were intended to be charitable donations.
But the donations, between £20 and £50, were changed by Mildred to large amounts. The court was told Enthony had benefited from his criminal activity by £299 – and a confiscation order would be made to recover the sum.
How much Miuldred benefited was "a little more complicated," the court heard, and a hearing against her under the Proceeds of Crime Act was arranged for January.
The case against both defendants was adjourned for pre-sentence reports, and both were granted bail.
But Recorder Stuart Rafferty told Mildred: "You have pleaded guilty to very serious offences.
"Stealing money from elderly people when in a position of trust is always to be regarded as a deplorable offence. There is a very real possibility that you, Mrs Mawarire, will lose your liberty."