You can try teaching her to go on command, when she goes outside treat and say something like (go or toilet) keep repeating every single time she does something, eventually she will understand what is expected of her.
As for accidents ignore it and take her straight outside, make sure you clean the area thoughly with a decent cleaner (no ammonia or bleach cleaners) so it takes away the scent of where she has been, dogs are more likely to return to the same spot if they can smell where they have previously been.
Four weeks ago we adopted a four year old Westie. She had been used in a puppy farm. From the start we took her out into the garden every hour and encouraged her to go to the toilet. After a couple of weeks she seemed to get the hang of it. Now the weather is better we keep the back door open and she goes out as needed. This week we have been able to start walking her. Things have now gone astray with her housetraining. She still uses the garden occasionally but will not go to the loo whilst on a walk. However, she has also taken to pooing in my bedroom. How do I get her to go to the loo outside or whilst out walking? We are going on holiday in the summer and this involves a five hour journey. It would be very helpful if she would go to the loo when we stop, not in the car. Thanks