There's web sites that scrape info about providers from other sites.  From what I've heard and read, it's difficult if not impossible for providers to get that info updated or removed.  

If it was a site this provider controls, then yes, that was wrong on her part to not update the site if not take it down upon retirement (or when changing her hobby phone number).

But a suggestion for the future, if I may:  if you're calling a provider on what you think is her hobby number and a guy answers, just say, "I'm very sorry, I dialed the wrong number" and hang up.  Even if it's still her hobby number, that might save you from other complications.

Very hard for us to trace all our presence on the net

Yes this would have been awkward!! It may just be that she hasn't been able to have all info taken off all the places her advertising pops up?