[gemy]

Yes I do. TAke her to a pet store or some other public environment. In the petstore, hopefully at a quiet time, explain to owner/clerk you are training your dog to sit stay.

And yes use treats there to reward, particularly if she responds well to treats.

Have stranger simply walk by you and dog in sit stay. Some distance away. If she ignores stranger reward. Don t have stranger stop at all - just ignore both of you. Then have stranger pause but look away turn there back. If she sit/stays reward.
Then have stranger pause look at you , he doesn't speak, and then moves on If she sit stays reward.
then have stranger pause look at you, say hello, and quickly walk past. She sit/stays reward.
then have stranger pause, look, say hello, shake your hand, and leave. Reward for sit stay.

It is breaking down the exercise in minute steps.

You can start at home with sit stay for her dinner.

Hope this helps. and best of luck