Emily is currently 100% off the ice because of her hip injury, and she is not allowed to practice again until the last week of February at the earliest.
She is in no position to petition for a spot on the World team, because it is highly unlikely that she would be physically able to compete after being completely off the ice for six weeks, and then having only 3 weeks to get back in shape before Worlds.
She would have to PHYSICALLY demonstrate to a committee that she can skate a short and a long program equal to or better than those skated by the top finishing eligible ladies at Nationals.
I don't see how she would be able to do that, under the circumstances.
Anyway, if Ashley Wagner is named for the World team, we don't need Emily. Ashley had a FS score of 108.15 and won a medal in the GP, and Emily went medalless.