I have bunionettes, i.e., little toe side bunions. My foot doctor gave me the choice of either surgery or wide-toed footwear. I've been using wide-toed shoes ever since and have no problems.
Well, it can be a problem picking shoes; some shoes that look like they should work don't, and it can take tens of miles, really about 50 miles of backpacking before I can be confident that the shoes I'm wearing will work.
In terms of specific brands, I used to like golites, but they changed their 'last' (mold) so that they got just that small incremental bit narrower so that I started having problems with newer models. Now I use an Asic brand Gel-Kahana model in 4E width, sized up 1 to 1-1/2 above my nominal foot size. These are very comfortable for me for all sorts of use. But male vs. female, bunion vs. bunionette, and just the general wide range of foot dynamics and preferences -- who knows.
If instead of trail shoes she's inclined to heavy poorly breathing boots then --- I have not a clue. My foot doctor, despite the suggestion of wide toed footwear, periodically tries to convince me to wear boots but apart from all the other ills boots offer, I've not run into any that I'm sure are wide enough in the toe area. Certainly none of the ones my foot doctor generically suggested for other issues would have worked. Great foot doctor I've got, but of course he and the vast majority of his colleagues have no long distance hiking experience personally.