Jazz, hon, you know it's early days for her. The real tests come when those little quirks of life come along for her to deal with, not when she's still on her pink cloud. I am not saying this isn't for real, but nobody knows if it is or not. Total and permanent change in thinking and behaviour in 6 weeks? (assuming rehab was 28 days, which it may not have been) Hmm..... I know it has taken me a good few years to change MY thoughts and behaviour and I didn't have physical addiction to deal with on top.
And you know from my experience that some people can talk the talk extremely well. It's the walking that's the hard bit.
Listen to your gut. But moderating hope is a matter of caution, rather than pessimism.