Please forgive me for playing devil's advocate here, but... did the breeder specifically tell you that the snake is NOT het for pied? If not, how do you KNOW that it isn't??? Pieds originated in the wild, so unless the breeder knew (through breeding) that she isn't het for pied, it IS possible that she is. Oh - even through breeding it would be difficult to PROVE that a snake doesn't carry a particular gene. Odds can be really bad sometimes.
Once again, I'm not saying she is or isn't. I'm just playing.
Steve