It is really depressing for me that one of the things Chessie said struck me as being true - it was a tiny detail that would be hard to come up with as a lie. It's about the Styxx river area being full of old shoes and items of clothing. I've noticed that myself, near rivers and especially the sea.
It does mean that anything less than a perfectly accurate description of what Brittney was wearing/carrying is pretty useless. And even then, it might be impossible to pick out any items of hers from among the other items laying about.
Having said that, what Brittney was last wearing might still be on her now. If someone hurt her though, I think they might have disposed of her bag separately, as they would have wanted her phone and any cash and maybe keys/papers. They may have forced her to reveal where she had hidden her letter and who she sent it to, as well. I'd be interested to know if any homes where Brittney stayed experienced a break-in shortly after her disappearance. Especially if the usual valuables weren't taken.
I'm just thinking of it in terms of events; if someone killed Brittney their number one priority would be to hide her body, and they would be unlikely to spare time to root through her bag first. Number two priority would be to take anything they wanted from her bag, then get rid of the rest.
Somewhere on an illegal trash dump on the RETURN journey to the perp's home, I think Brittney's looted bag is still there. I also think there may have been enough dumbness around that some of her items may have been kept in someone's home. Sadly though, the only people who could identify them with any certainty can't be relied upon, in my opinion.
It may seem unbelievable that anyone would steal a few dollars from a deceased girl's bag, or keep a few trinkets/items that took their fancy, but I wouldn't put anything past a person/people capable of harming a 19-year-old, with her whole life ahead of her.