I guess it depends whether she is actually clean and what substance she’s clean from. With my husband if he’s taken any cocaine at all, even if he visibly looks sober at the time, all his problems will be someone else’s fault and it’s a sign he’s been doing it or at the least associating with people who do as his whole attitude changes to the world being against him, when he’s not drank or taken anything he admits his wrongs and talks about wanting to do better etc but this can change the very next day if he’s taken something.
