Gender bender

So I got my baby snake Kyna sexed about 2 months after i got her. The vet says that she is a girl but she seemed like she wasnt quite sure. I want to get a mojave ball python as a mate for her in the future but i cant get one until i know if she is actually a girl. So here is the question. what do you think is the best way to figure out if an 8 month old ball python is a girl or boy. Probing probably right? well how should that be done? like how far for a girl and how far in for a boy on an 8 month old..

What method did your vet use to determine the sex, and was she experienced with herps? I know that I had one of my girls sexed and doubted her gender when I found what looked like a sperm plug. I have no idea what it was, but she was definitely a she, since she laid 6 beautiful eggs for me this year.

Oh thats wonderful congrats!!!!