If anyone has watched Young Justice, Green Arrow had a sidekick in that show named Artemis Crock. She was basically that show's version of Arrowette, a fan girl of Green Arrow who became a vigilante as well. Her story was that all of her family memebers were either currently or formerly assassins. Her sister and father were even memebers of the League of Assassins. I found this made her interesting because her interactions with her teammates and family give her a complexity that made her great to watch.
That being said, would anyone be open to seeing Artemis in Arrow? Her family would fit right in with the show and I think she could be an interesting foil to Roy and Thea.