Susan Hadlow, 60, was convicted of taking £47,137 between April and October last year from the WRVS shop at the Royal Glamorgan Hospital in Llantrisant, where she was employed part-time.
The thefts came to light when staff at WRVS head office noticed during routine checks that till rolls did not tally with cash submitted.
The judge at Cardiff Crown Court also revealed that Hadlow had been given two suspended sentences in the 70s for stealing from employers and a fine for forging cheques.
The charity emphasised that it had not been aware of Hadlow’s previous convictions and confirmed that she had now paid back all the money she stole.
Hadlow’s barrister said she had always intended to repay the money and had stolen it only because she was desperate after she and her husband became ill and had to give up their jobs.
After the case, Hadlow told the South Wales Echo: “I’m very sorry that I’ve caused the WRVS all this trouble. It should never have come to this because I should have got help.”
A spokeswoman for WRVS said the charity’s financial procedures had been tightened since the theft had come to light, with the introduction of a whistleblower’s hotline and an increase in the frequency of checks on cash balances from monthly to weekly. “But there are lots of projects and things can get delayed and overlooked,” she added.
A WRVS statement read: “As a charity, accountable to the public, we do not tolerate any mishandling of money spent at our shops and cafés or donated to our projects. We will always take effective action to ensure that our projects are run transparently and with appropriate financial control.”