I'm guessing you are actually talking about Army MOS 18 series. See there has been female in Special Forces groups for quite awhile? how? because there's more than just 18 series soldiers in a Special Forces Group.
they literally just opened them all up to women. the standards are the same though, so unless youre as strong as some of the strongest men in the military i suggest you look into regular combat.
If you do think you might make it i suggest TACP in the air force. you'll get the awesome support of the Air force ameneties and you'll see combat and be concidered spec ops (at least inside the AF)
Most Or even all forces contain Female forces. Some Third world countries may not have female forces, If any. It honestly depends on how developed the country is. If the country is similar to that of the year 1700, It is most likely that the country is based on a masculine military force, And not based on Feminine And/or Masculine. Overall, It depends if a woman can handle the training, Of which many can. The reason you don't see many Female Military troops is because of the evolution of which gender is specified to other tasks, But that is for another question.