I myself do not care for makeup as a hobby, but I wholly understand the idea of it being a popular hobby, as well as an art form. It is no longer just "Oh, I'm just going to use it to get ready to go out." It is now as much art as paint to a canvas.

The petty side of me is screaming to speak up; every now and then, if you feel up to it, show off your makeup skills. Do it to yourself, and even those kinder people around you and watch her squirm knowing that some "gender confused girl who is wasting money on a silly hobby" is better at it than her. If she somehow sucks up some of that ego of hers and asks you to do hers, tell her something along the lines of "Oh auntie, I couldn't possibly do that! Its just a silly hobby of mine, and I couldn't possibly do you justice!" customize this comment however you like. Smile politely to make the jab extra subtle, and watch her fume.

Buuuuuut that is just the petty in me, and would not actually recommend that unless you are also feeling petty. However, if you ever do decide to get rid of your makeup (no pressure at all, it is a wonderful hobby, and you are doing great with it. You have every right to use every bit of it.) make sure it goes to somebody who YOU feel deserves it. This woman's poorly-disguised thirst for your makeup makes Mr. Krabs look generous.