She is probably just so anxious to get back inside with you that she goes on the step. Kalina always went potty in the yard until she had her puppies - then she would go as fast as she could and as close to the house as she could because she was so anxious to get inside again! I agree that you should take her out into the yard and stay with her until she pees. She probably likes you there and loves when you praise her. I had to start going outside with Kalina again for a while, even though I don't always want to, believe me.
