Here's the thing to remember about this journey. There is usually some adjustments to make before you arrive at your destination.
I don't remember the jewelry. I apologize if you mentioned it. My memory isn't as good as it once was. Let me clearly state that when a WW has ended contact with her OM, nothing can be saved that had any attachment to the A/OM. That's why all old texts, FB, photos, etc., must be deleted. No keepsakes from their hangout, date, or whatever, can be saved. And most assuredly, no gifts from OM. Wearing his jewelry is her message to the OM that she has turned on the green light.
I understand being cautious not to appear paranoid, but you really should have asked about the jewelry. You are her H, and if she's clinging to anything sentimental from OM.....it has to go. It makes no difference how much she likes it, how expensive it may be, or how nice it looks on her. It will forever be an attachment to OM. She should place your concerns and need to feel safe in the MR before her friends, things, and certainly anything connected to OM.
Put this jewelry with her new, sexy clothes; going out again with BFF; slacking off the MC homework and not following through with IC; and not wearing her wedding ring after reconciling.........adds up to reasonable doubt. I understand how her momentum could lower about the MC. I don't fault her for the new clothes. Not wearing her wedding ring and then putting on this questionable jewelry.........worries me.
I don't tell many people to do this, but I think you need to either put the surveillance up, or talk to her about your feelings. If she agreed to transparency, then she doesn't have anything to hide.........right? But your gut continues to protest. If the two of you have agreed to work on the MR.....then you are allowed to talk about how all of these actions cause you concern. After all, she cheated on you! IMHO, she is beginning to fall away, and she may think she has you in a place of trust for a while linger. Perhaps it's the effect from visiting with BFF, IDK. She has not worked enough to earn your complete trust, yet. But that's just my thinking.
Check it out, and if nothing shows up.....take the surveillance down again. It's spot checking, or as some call it.....gathering intell. It may relieve your mind.......or you may see something that is devastating. You have to decide what you can live with, and what you can't stand not knowing.
((hugs))
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!