Such is the internet, it's a first for me to be called ludicrous

. Especially when my statements are based on a bit more than conjecture or personal experience! I think you're justifying your experience with a bit of rationalization and then adding a pinch of bad science there to support what you've done.
13 is at the very beginning of puberty. The
OP is a girl, and especially for a 13 year old girl and given the way sex works, she's not ready. The physical parts involved with sex are in all probability under developed, and so are the emotional ones. The results here are usually not good, I hear a lot from people (of all ages) who have had early sex, and based on how unsatisfactory it most often is...is by far more related to sexual (and relationship) dysfunction than anything else, surely not "Waiting", at least until puberty is far enough along so everything works properly...and there's a bit of emotional maturity in place to help deal with the many emotions that inevitably occur with sex.
The
OP is obviously free to choose as she wishes, however, if she wants a perspective based on experience with other kids who have done what she is contemplating, the overwhelming data supports waiting.