If you actually have the magazine, I would recommend checking the fine print at the beginning and the end of the mag. The U.S. Elle lists all items of clothing, and usually the hair and makeup products used in the cover shoot, and I would say that the U.K. Elle does as well. If you could find where they list her clothes, etc. then I'm betting the bracelets and necklace would be there.
If not, then you could always e-mail someone from Elle, they are usually good about answering e-mails about the items featured in their magazines, or you could look for it on the Elle website under that issue.
Really hope you find them, they are gorgeous!