Speaking as someone who has been blessed with a bit of experience with female genetalia at eye level, I've seen women with tiny labia, puffy labia, and some that are full and flappy. As a point of fact, I'm a little wrinkled there when not aroused.

There are some tribes that do labia stretching but I dated a woman whose lips were at least three inches and she had never done anything to get them to that state. Like breasts, lower lips come in all sizes and varieties.