Litter box training a 4 month Papillon pup

Question
We recently adopted a beautiful 4 month old female Papillon pup named CC and are attempting to litter box train her her.  Unfortunately, after 3 weeks of trying, we continue to have no success.  Do you have any suggestions?   We've been told that she's get confused if we try both the box and outside training?  Thoughts?

Answer
Well what might work is if you put down puppy pads in the spot you plan on putting the box on,as she will get used to using that one spot

It might be a good idea for a while to just get her litter trained before moving her outside as it will confuse her