I am a black female with natural hair and I was wandering what would happen if i put an S Curl in my

You'll have an S curl in your hair. DUH

I am a black female with natural hair and I was wandering what would happen if i put an S Curl in my hair?

You hair will no longer be considered natural. You would have altered the texture by using a chemical. On top of that your hair will be greasy and oily looking. Stick with your natural hair. There are plenty of products out that won't alter your natural texture permenantly, but will define your natural curls.