DeVere sounds like a pretty great, chill grandparent. Honestly, so long as she stays out of the areas where they're holding protests and the routes of the marches (and that's easily accessible open source info), she's not really in any danger, IMO.
As for evac, I think she can contact the embassy for a recommendation on a fixer. But worst case, the embassy also helps all Americans get out in bad situations.
And she's not entirely isolated besides the boyfriend. goEMAW nation has a representative there in a pinch.

Oh, and on housing, feel free to run proposed neighborhoods past me. I'm not entirely ITK on the whole city, but I know good spots and bad spots. If I was her, I'd live in Zamalek. Garden City/Talaat Harb is really cool but also more protesty.