Can rehab prevent prison on repeat drug charges

My sister is looking at her 3rd possession charge and is worried about the possibility of getting hit with prior and persistent. Her parole officer Is aware of everything and is telling her she will do a delayed reaction on her parole and is having her turn herself in on the warrant and get bonded out. How do you think this will all play out. She just did 2yr and 9 months for burglary it was her 2nd commit at 40%. can she avoid going back prison since her parole officer is sending her rehab. Will the new drug laws help with lowering her chances of the prior and persistent charge