Maddy,
I like Cookie's idea - people often value things more when they know how much they cost and how much time they take. She probably has no idea how long it will actually take you to make the cake.
As it is your gift to her, I would ignore her demands, and make a cake that you are happy with. I would definitely break up some of the pink with green leaves, and add glitter if you wish. She has asked you to do it because she admires what you have made in the past, and your particular style. You are entitled to artistic freedom.