Bella is just over a year and she has been completely potty trained since 5 months (the little ones do seem to take longe than the big ones). She hasn't had any accidents. Even when we're gone at work/school for 7 hours and she's in her x-pen she doesn't "go". Some friends of ours watched her for 3-days when we were out of town in October (she was 7 months) and she never had an accident at their house. I fully believe with consistency and repetition most any dog can be potty trained (though I'm sure there are exceptions but I think it's rare). My friends who watched her for us have 2 Shi Tzu's that are about 2 & 3 years old and they still occasionally have accidents but it's because they've never been properly potty trained and shown what's expected of them (even my friend will admit this is true). Don't stress out, keep doing what you've been doing, stay consistent and I'm sure you won't have any problems. Good luck!