19" is really to big to overt the hemipenis (pop them). Popping is when one roles the thump up along the tail towards the vent to see if the hemipenis can be overted. This also takes time and practice that you should only learn from a more experienced keeper.
What you need to have done is probe the snake to see if it is male or female. probing is where you take a thin blunt steel pin/rod (probes are sold at reptile shows) and insert it on the side of the vent towards the tail (not towrds the head) and if it goes down 6 or more scales it is a male. If it stops at 2-4 it is a female.
You can also post a pic of the underside of the tail (vent to tail tip) and we can make some educated guessses. But guesses is really all they would be. If you want to be 100% sure you should get the snake probed by an experienced breeder.
Do a search on "probing" here and then go to the classfieds and look for probes to veiw a picture. You might get lucky and find comprehensive pictures of what is involved with probing.
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I don't need no spell chack.