If anyone needs this here’s how I did it:
ensure jquery is loaded into WP.
jQuery(document).ready(function() {
jQuery("ul ul li.widget_subpages_current_page").parent().prev().addClass("widget_subpages_current_page");
});
this will add the class “widget_subpages_current_page” to the preceeding elements parent in the DOM from the child item that is selected. (I think!) A bit of a hack but seems to work 😉
+1 for that update. highlighting parent of current page would be super useful 😉
