Also just a thought, but are you picking up her messes and putting them outside so she can smell it out there where you want her to go. We have two OCD border collies and they run the routine here. I don't have to even talk in the morning they know who goes out first then they exchange places at the door automatically (we put them on a chain in the morning to do their business). They both sniff around a different area and they both have a favourite spot. One by the garden the other behind the garage. They seem to spend inordinate amounts of time sniffing the chosen areas! Considering that they have been using the same spots for 7 years! (Unless it is raining then they are amazingly fast!)