Welcome to YorkieTalk. You have been loads of great ideas to help keep your little missy safe from roaming bachelors. You could try rubbing a bit of Vicks Vap-O-Rub in the hair around her vulva - but be careful not to get any ON it. The smell will help mask her "in season" scent. We used to rub out stallion's noses with good ole Vicks when they had to be around a mare in heat. Like I said, Vicks may help some, but won't deter a determined stud.