I have just spent some time trying to see where you made that comment Nellie. I was looking for a comment made prior to mine. Now I realise that we both posted on the same issue at the same time.
If the National Gallery's date is correct then QM definitely cannot be wearing the chain link bracelets/choker. That in turn, suggests Arthur is on the right track.
I would like to sound a note of caution about the National Gallery's dating. I know it is often wrong. For example it has a photo dated in the 1890s showing QM wearing the Delhi Durbar parure