Most Wordpress plugins that offer a sidebar widget include a "Title" field in their widget. If the Title field is empty, no title appears and the H2 for that widget is omitted. However, if the widget includes a title, it renders for that widget. It's a small thing, but it's easier and less clunky than putting a text widget above the login widget with the title "Member Access" with blank text and then putting the login widget below. It may not be a high priority, but it's certainly an easy fix.