Is she using something like hotmail, or is it a work account? If it's hotmail or yahoo or something, tell her to go into the filters section and fill in words to filter mail to her trash. Words together like "credit card" "big savings" "great deal", etc. are usually what will keep a lot of the mail out. I would just use every filter with the most common words that she gets. Then, every time after that she gets spam, tell her to click on the mail and then click on "block senders"...there are usually about 100 blocked senders you can put on the list. This helps me control it...
Otherwise, take everyone that she emails, put them on a list, get a whole new email account and let everyone know about it. And NEVER put it onto a site again unless she's absolutely sure they won't sell it.