The time table for “healthy “, even with diligence and hard work on the addict’s part, is more likely measured in years, not months. Relapse, usually multiple times, is the more typical outcome out of rehab, even if they eventually do find real recovery. That can take decades for some, or never happen at all.
I gently suggest moving on with your own life and not waiting to see how it goes. I hope you both get the best case scenario, but hope is not a plan nor a future fact.