Alxtabs widget – choose posts by tag

I really love the Alxtabs widget and how you can show a list of posts with thumbnail, title and category.

I have a set of posts I would like to display under my What’s Hot? section. They aren’t the most recent or the most commented, but they are posts I want featured. I would like to create a tag called Featured and be able to have the widget pull just these posts, but that isn’t an option. Instead, I created a category called Featured and am using that, but I really like showing the categories and I don’t want this extra category to show up. You can see how it currently looks in the left sidebar here:

http://futureexpat.com/

Is there CSS I can use to change the widget so it pulls a tag called ‘Featured’?

I’ve never tried to create a child theme, and would rather not have to do that.