If you are physically fit I think you can adapt to pretty much any size cock in your pussy. Your pussy has a lot of muscles if they are well toned they can grip a variety of cocks. Of course if your pussy is used to being stimulated by a serious BBC a small cock will not bring the same level of pleasure. Personally I think if a woman is sexually active you don't really need to worry about loose pussy. If you are concerned there are always Kegel Exercises. Done regularly you could probably grip a pencil or a pencil cock with your pussy.
It was a very long time ago, I was 12 0r 13 (I am 63 now) and the girl was about the same age as me and white. I was scared I would get caught and she was adamant that I was going to fuck her. Even though she was the instigator I think I enjoyed the experience more than she did.
In high school she was 15 or 16 I don't recall. In recent times, she was 20, I asked if we could hit another bar for a drink and the truth came out, she was in the bar we was in because she knew the bouncers, so we just went back to my place and fucked.