Hardly anyone but family gets it right, when they see Ella and Eric. It's easy to notice her, the obvious one, the face of the pranks or the punches, but too many forget about her twin, her not-a-shadow standing nearby like the moon orbiting the sun, perhaps with his head in a book. That sure doesn't stop him from being just as observant as her, absorbing information on anything from science to tech like a sponge - and, when necessary, taking action with a little more subtlety against whoever dared to harm their family.
Then Eric is gone-gone-gone and she's the sun, burning up, no one can stop her like he could've.