The information about Michele Citon was taken from this paperweight seller's web page:
http://www.muranopaperweights.co.uk/millefiori.html
Wright, the info may have appeared on Jackie's site, but the words were Leni's. There is no plagiarism involved here as seems to be implied.
If we take your comments to their extreme, then everytime anyone comments on an attribution we will have to find every site that uses the same information and quote the links. This is not what a knowledge site is about IMHO.
No knowledge exists in a vacuum, everyone has learnt their information from books, websites, lectures, conversations whatever. Plagiarism is when somebody takes someone;s words letter for letter and passes them off as their own.
End of my comments, any further comment would belong in the cafe.