It doesn't sound like aggression to me--when chickens are being aggressive, they tend to puff up and aim as high as they can reach, and they usually use their feet as their primary weapon. It is still a behavior you will want to correct, so gently remind your hen with a push or a tap that her "gimme gimme" attitude is not groovy with you. You don't have to hit her or cause her pain--just remind her that you are the biggest and strongest. A humbling cuddle session may also be helpful, depending on the bird.