Puppies don't have the best bladder control and this is a fairly common problem. Try to prevent accidents by removing her water bowl and give her plenty of opportunity to empty her bladder in the half hour before your guests arrive . When your guests do arrive, make sure her overexcitement is not rewarded. Have your friends stay calm, ignore the behaviour, and don't lavish her with attention.
My Miniature Schnauzer Is 7 Months Old And Pees Everywhere When Guests Come And She Gets Excited, Can You Please Help Me?
I raise mini schnauzers. She has an nervous bladder. Try ignoring her when you first come into the room, tell your guest to do the same. Don't talk baby talk to her, after seeing everyone for a few minutes she will be fine. There is no cure, but this will definitely help.