I would definitely speak up. With my pups I required friends and people we knew to wash their hands to hold them bc they were babies. And I do not let people pick them up either.
With Susu he is not stranger friendly and is rather anxious but loves to go on errands. I always ask people not to talk to him, look or him and certain they cannot touch him. He does freak out. He does great if everyone ignores him otherwise the barking starts. I have found people to be very respectful of this. I just let them know that he is very nervous and they let him be.
Just let people know they can pet her but not pick her up and I think they will honor that.