Hi i`m thinking maybe the female will follow the trained male yorkie and when he goes you let the female go woth him this way it will teach her to go to the toilet outside, i have rescued a yorkshire pup that was strayed at christmas and i have a border collie and she is doing what he does they are so funny together daisy mae is my 6th yorkshire terrier
The best way to train a puppy is to put it outside every couple of hours and reward it with praise and attention when it goes outside (this also means you have to go outside and stand with it). Praise works wonders on a dog. Also, don't leave food and water out for the puppy. This just encourages it to go whenever. By putting it out and then directly taking it out after it's finished, it gets the idea that that's where it needs to go. And definitely put them out together. She'll learn faster when imitating another dog.
I have had a hard time with mine but my best advice to you is be consistent in what you do...if you want them to go out together take them out together every time. You must also thouroughly clean up the messes she is making or they will continue to do so, the smell triggers the response it is natural. A good enzymatic cleaner will help get it up.
Crate training is the best way for any pet to learn potty training. I have a 5 year old male yorkie and is the most stubborn dog I have ever owned. He still has accidents from time to time but mostly when he dies it is my fault and I haven' let him out quick enough. Try the crate training method, it works!
Your best solution to house soiling is to have SET feeding times therefore you have SET toilet habits. Puppies need feed 5-6 times a day (5-6 times out to potty) & then you wean them down to 3 times a day as an adult to eat & potty. If you free feed then you are allowing for free soiling also.