It's tricky to recommend, Roger - most of the journals contain articles on quite diverse subjects, often meaning you've spent a fair whack to read just the one that interests you. I'd definitely recommend her to visit a good library and have a browse through the ones they have, to see if any look interesting to her. Personally, I've only ever really used journals to access the one article I need, and usually ignored the rest. I generally find books more engaging and they often cost about the same.
Not much help I guess, but I do think a trip to the library might help.
eta - I just had a quick look at
Art History (Journal of the Association for Art History), the content of the current issue has nothing that would interest me; then checked
The Burlington which had a good few that might, then noticed the current price tag - 28 GBP! (
https://www.burlington.org.uk/current-issue ).