Hi Jen,
Good point – right now it looks like the core “embed Google map” code doesn’t add a title to the resulting iframe. We’ll fix that in our next release, but in the meantime here’s something simple you could add to _ingredients/themes/global/scripts/calendar-custom.js in your theme to patch in an immediate change:
$('body').bind('calLoad.lwcal', function (e, controller, data) {
$('.lw_cal_event_detail_map').find('iframe').attr('title','Google Map of event location');
});