Why Won't She Pody Train

We have a 14 week Mini Australian Shepherd who decides when she wants to be pody trained and when she doesn't. She had two weeks where she didn't use the house at all. Now some days she decides that it's ok to use the kitchen, then the next day she'll go outside every time and within the last few days she's decided its ok to go on the carpet again too. Mostly she pees when she goes inside but once in a while she'll poop too. We've tried to Kennel Train her and we reward her every time she does outside and spank her, rub her nose in it and put her outside every time she does inside. We've even limited her water take it. Nothing is working with her. We'll be playing with her not 2 feet away from her and she'll just stop and pee right there in front of us. HELP US!

Note from Anton: Info about "The Ultimate House Training Guide" here.