Is it normal just get a birthmark or mole on the labia major?

Yes.: Moles can occur on any part of our skin as they are simply a population of closely congregating melanocytes. You actually have melanocytes everywhere you have skin. However, the reason you can't see them as a brown mole is that you only have about 1 melanocyte cell for every 10-15 keratinocyte cells. With moles, you have a bunch of melanocytes clustering together to give the appearance of a mole.

Yes but watch: Certainly moles or pgimented lesions can occur anywhere on the body. However, it is key to keep an eye on the size and shape of these lesions with the acronym: abcd whcih stands for asymmetry, border characteristics (irregular), color variation (more than 2 present), and diameter (greater than 6mm).

No: If you have a mole or birthmark on the labia my recommendation is to have evaluation by a doctor to make sure it isn't cancer. If it is benign then you don't need to worry.