Study Hall Freelance Journalist Forum

First, that's so incredibly cool about your grandmother, and I would love to read this! Second, my first thought would be Paste Magazine? Third, if you want to cast the net wide, you could always get a 1-month subscription to Study Hall freelancers' forum and post the question to their listserv - the community there usually has great sense of what editors are currently looking for where, and you can also use the database to search editors emails at different pubs.