Being new, and scared can do it to any new pet dog or cat. Also she could be kennel trained, but that doesn't mean that he/she isn't going to be house trained. Alot of times in shelters, kennels etc. most of the dogs are going to be strays so they don't know fully that they are house trained or not. Keep working with her. If possible, put a doggy door that leads outdoor and give her a small kennel/playpin to be in while your away. Take her out right away in the morning,after she sleeps,eats,play and praise her deeply when she does it right. A dog should be taken out 4-6 times a day.If the neighbors don't give you the look of is this lady nuts? then your doing it wrong. And you have to out stubborn her. Rubbing their noses in it, does nothing so stop doing it, and consider crate training the dog. Perhaps a visit to the vet to make sure she is healthy is needed (ether way it wouldn't hurt) but most likely its just a transition problem that with time and work will sort out. Deodorize the places that she has peed and pooped to. It helps to be patient as well.