The twin sister of a disabled man whose care worker stole £56,000 from him and another young man says she is angry she got away with it for so long.
Yolande Howells, 40, from Gorseinon, near Swansea, is beginning a two year jail term after admitting fraud.
Merthyr Crown Court heard the care company manager in Rhondda funded a luxury lifestyle of Caribbean cruises, cars and clothes with the cash.
Julie Williams said it had been an "absolute nightmare".
Her brother Anthony, 49, who has Down's Syndrome had £22,000 stolen.
She sad: "(I'm) very, very angry that she got away with it for so long.
"I'm just relieved now that it's all over as it has been an absolute nightmare for the past 12 months.
"Especially after finding out she could actually do something to vulnerable people, and especially my brother."
Merthyr Crown Court had heard that Howells, who had been a regional manager for healthcare firm Shaw at a complex in Treorchy, Rhondda, was a "compulsive spender".
Prosecutor Rachel Knight said: "Howells spent the money on cars, catalogues, clothes - she had a compulsion to buy anything.
"Although she helped herself to tens of thousands of pounds from the two young men she was still in debt at the time of her arrest."
Howells took £22,000 from Mr Williams, and another £34,000 from the second man after making them write cheques.
She forged Julie Williams' signature on the cheques.
The court heard one of Howell's colleagues suspected something was wrong and raised his concerns with the Cardiff-based care company.
Howells resigned before her arrest after suffering a breakdown from the "guilt" over the missing money.
Judge John Curran said Howells had been "deliberately and persistently deceptive".
After the case Julie Williams said: "I realised something was wrong and went through the bank statements which I then passed onto her bosses.
"She is meant to be a professional carer not a thief stealing from the vulnerable. I'm just glad in one way that Anthony isn't aware of what has gone on."
A spokesman for Cardiff-based Shaw healthcare said police were called in after fears were raised about Howell's spending.
He said: "The welfare of vulnerable people in our care is, and remains, our highest priority.
"We totally condemn any actions that undermine the trust between service users and our employees."