Just like anything professional, modeling is a skill, excelling in it does take work and experience to be a great model and a model booking work.
But that isn't all.
When you are a new model you have to be persistant, you have to do your homework - get a compcard, focus on your photos,- and mail them out. Massive mailings is so important.
And also knowing your look and your body is important as well. Being able to quickly get in the modeling vibe and mood and adjust to any atmosphere and set. You will be working for all types of jobs and just like you are paid, so is everyone else. So you want to be able to know your body and self enough to know how to quickly angle your body, whether it is for a shoe modeling job, or calming your face for a makeup or cosmetic shot.
Modeling is a skill. It takes practice and it isn't something that a girl should expect just comes naturally.
It can take a lot of work to get rolling as a model, and get an agent, and things don't happen over night, but if you really want something you are up for the work and challegen, and if you want something you really try, really, really try, and you are smart about your pursuits. Just remember, treat modeling like a craft you will be a model for hire and hopefully hired alot.