Telephone privacy

Last week I brought my ATF to a facility for drug detox. I stopped at a convenience store so she could get quarters for the pay phone inside the place. She was gone about 6 or 7 minutes and when she returned she had just shot up a gram of heroin. On top of several Xanax she had taken she was pretty well blasted. I waited as she went through the intake process and she came back, handed me her pocketbook and her cell phone and asked me to hang on to them.
Yesterday I picked her up after a 5 day stint. When she checked out her personal belongings were given to her and she asked where her phone & bag were. I said I had them in my car. She told me that she had no recollection of checking in and was amazed that I had them.
Now, I had her phone for five days. Should I have checked out her photos, her messages, her other friends? Of course I did. For more than 6 months she has said I'm her only OTC customer and from what I could tell, that's the case.
Her messages with her BF/baby daddy were quite explicit but supported what she told me: he won't see her till she's been clean for 2 weeks. There was a message from a new customer who she's only seen in the club and she says he's BF material - hot, ripped body, owns his own business at age 30. She doesn't view him as P4P material but says he tips very well.
Everything else was all about the constant quest for drugs. I know the first names and phone numbers of about a dozen dealers, for what that's worth.
Her photos included several totally nude selfies, which shed already sent to me. No where near the stuff I found when she left her phone in my car 5 or 6 years ago. A question for the assembled masses: should I have gone through the phone?