This question pertains to USSSA rules: If you are playing with an additional hitter (AH), then your team is batting ten. If the AH comes in on defense for the pitcher and the pitcher goes to the bench, are you now batting with nine? Is this considered a substitution? If so, then the pitcher can come back if she still has her re-entry and you then go back to batting with 10-is this correct?

In USSSA the AH position never disappears, and must be there the entire game. In the event that the AH plays defense for anyone, you are still batting 10 players. (This includes playing defense for the pitcher.) They would all bat in the position that they are listed on the line-up card. The rule is 6:3. I believe that you can view the USSSA rule book online.

So if the AH goes in for the pitcher, does the pitcher continue to bat in her original spot in the line up (even though she is now sitting on the bench during defense) along with the AH who is now also playing defense?

Yes, your batting order never changes. Only the players name,
if a substitution is used.

glen