So you have. Here may be relevant:
https://chrome.google.com/webstore/detail/photo-zoom-for-facebook/elioihkkcdgakfbahdoddophfngopipi?hl=en
WE WERE HACKED!
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8/31/2016
First off, everything is going back to normal with a new build being released.
Someone hacked the most popular extension on the Chrome store and was able to update it with malware that redirected users to bad advertisement websites in a ploy to make a quick bucks.
It is infuriating that someone was able to do this, but we have removed the malware and are back on track.
As always, Photo Zoom does not want to run on any sites other than ours and Facebook (obviously) and certainly do not want your data at all.
We are so sorry for the inconvenience!
It’s bizarre to me though that this report was from nearly a year ago so this may be a red herring. Also flagged up is GoPhoto.IT and OptiBuy. The latter is interesting.
https://www.pcrisk.com/removal-guides/11280-optibuy-adware-mac
My guess is that she’s installed some software / download recently that has come bundled with adware and she’s failed to untick the “yes, please install lots of shit” box, rather than it being a drive-by on a website. Though I’d need a) access to the box and b) better knowledge of the Mac platform to give you anything approaching a vaguely definite answer.