if nothing protrudes, then the likley hood of requiring a labiaplasty is low. the labiaplasty procedure performed is guided by the wishes of the patient. the plastic surgeon will inform the patient whether her request can be reached and what the limitations of the surgery are.
Even if nothing extra protrudes, re-shaping, and re-sizing the labia can achieve good results. Re-shaping, and re-sizing, should be done with mutual consultation, and surgeon must respect wishes of the client, which are achievable.
Some time you need to combine clitoral lifting surgery with labiaplasty in order to achieve the perfect results you are looking for. This needs specialist surgeon who knows how to work in this area. The size is something you have to discuss with the surgeon. To decide, you need to ask him and review before and after photos in order to choose the best for you. The surgeon always must respect the patients desires and wishes.