What should girls do if they have double chins because of prominent Adam's apple?

First of all, we must understand that women's Adam's apple is rarely as prominent as men's, unless a small number of women's androgen is too high, resulting in a slightly obvious Adam's apple, but this is also when your body is relatively thin. As far as your problem is concerned, being thin can't have a double chin. Obese people have thick sebum on their chins, so they look like double chins.