I'm no expert, but it sounds like you are doing to need to go ba k to the basics - only give limited access ( like an X pen) until she starts going where she is supposed to then gradually give her more freedom.
Someone with more experience can weigh in on whether the two pups are influencing each other I the potty issues.
I have heard many say that this has happened.
Goog luck!
__________________ .  Cali  , and Cali's keeper and staff, Jay No, not a "mini" Yorkie - She loves to motor in her Mini Cooper car |