Sorry had to make that 2 posts. The idea is to have a display without creating liability. Imagine how it looks from the other end. Dog takes up a position between someone's legs and starts barking its fool head off. You want to really take a chance with that? Its not bite training however its something and most people will think twice about messing with you and your "crazy barking Shepherd"
I'd honestly train her to bark independently of anything. Just bark on command. Same with a stop barking command. Its literally "Speak". Then you build the bark so she learns to bark more than once.
Alternatively when your not teaching that you teach the "location" command. Call it whatever you want. The dog takes up a position between your legs facing out (the same way you are) so its standing between your legs. .
Then you put them together. "Location" so the dog goes into that position between your legs and soon as the dog gets there then its "speak" and the dog barks, you reward.