I would give it time. I am sure that your friend did not mean to throw everything off. If you read the YT Potty Log you will see that even the most consistent owners furbabies have accidents from time to time. Yorkies are very smart dogs. So with that said, I am sure that your baby will catch on again. Keeping a schedule is also key in potty training. My girl is 9 months and is trained to go outside but still has an accident if I get off schedule. Just have patience . It will pay off in the long run