can you get out of court ordered drug rehab early?

i know prisons do go behavior and such. is there anythiong similar for drug rehab? my fiance was sentenced to 9 months in a pine bluff Ar drug rehab facility and she doesnt have a drug problem. will they reduce the time if they figure that out or does she have to stay the whole 9 months even though she doesnt have a problem?

: http://alcoholdrugstreatment.info/can-you-get-out-of-court-ordered-drug-rehab-early-2