Searching for a half-forgotten comic

Some time ago, a couple US president administrations back, I read a comic online dealing with two sisters - one normal, one with superpowers. Their parents were trans-dimensional energy-based aliens and the superpowered sister announced herself at a press conference, which was followed by a scene of assorted military figures worrying she might declare war on the world at large.

While I read it online, it may have been published and sold in comic book stores.

Does this ring a bell for anyone? What I remember is either too general to be a useful search term, or too specific to have been indexed anywhere, and I can't for the life of me recall the title.