This is so sad, knowing how difficult things have been lately for Alison Carey.
The 55-year-old woman -- who's the older sister of superstar Mariah -- was arrested in the upstate New York town of Saugerties on Friday following an undercover prostitution sting by police.
Alison was booked on a prostitution charge into the city jail, after cops allege that she was working illegally out of a local hotel and soliciting money in exchange for sexual favors to an undercover cop.
Police are also concerned that the woman, whom they described as a transient, is HIV positive.
Authorities are now encouraging
[Image via Saugerties Police Department.]