It's excitement/submissive peeing. The best thing to do is to act very casual around her when you go to take her out. Ignore the wetting and clean it up without making a big deal. Tell your friends to keep it very low key and avoid eye contact when they first walk in the door. I know it sounds silly but its the only thing to do. Some basic obedience training and puppy classes will help build her confidence.
Caretaker of 2 dobermans,, 1 schnauzer, 5 cats, 3 goats, 1 parrot, 1 bearded dragon lizard, 11 chinchillas.
Rest in peace, Cricket, Casey, Bella, Yank, Chloe and Bones.