I think it would also be safe enough to bring Jolly home if all of your dogs are current on their vaccinations. Like Kfamr pointed out, they've already been "exposed" to Jolly and anything she may have just going on walks with you. We bring in strays all the time and have no idea what they do or don't have. While we don't immediately let them have direct contact with the other dogs, they are still in the same house and we haven't had any problems.