Strange text message. Sounds like she was familiar with recreational pharmaceutical subculture. Every time you purchase illegal substances you face the dual risk of being arrested or robbed. Long time users develop a sixth sense about such situations. Somebody who's been there and done that usually knows how to recognize and navigate their way out of sketchy situations.
If she had been clean and sober, possible she went with people she didn't know to score and relapsed. The risk of accidental OD is highest coming out of rehab or off of a sober period. Your tolerance is down. Very risky to dose at the level you did before your clean stint. Also if you're getting gear from a new source you don't know the strength/purity.
That she hasn't accessed funds, as far as we know, suggests that she isn't on a relapse bender. As she'd be withdrawing money constantly to re-up.