I get messages daily from girls who tell me they are too short to model, or until they read my blog thought they were. If you are short you should focus on using what you have. This means thinking beyond fashion. Print modeling is what you should focus on and also tv and commercial jobs.
Photography is second, it comes before your mindset is ready. You should have in mind the modeling jobs a shorter girl can do and you will find girls of all heights, shapes, sizes, and ethnicities modeling in the print modeling world.
If you are not tall, and fashion is not likely then focus on getting great headshots, beauty shots, focus on the parts of you that can translate into the advertising world. Focus on the products that use models that are not always fashion height.