How do I potty train a very skittish Toy Poodle?

My new puppy Nala is extremely skittish. She is 14 wks old, and seems very uncertain of myself and my fiance. She will come and play with me when I lay on the ground and coax her out of her hidin whether it is under the table or couch. She will even climb on my back when I lay on the ground. The second that I try to stand up or look at her while I am standing, she retreats to her hidins. I have tried treats and using a friendly voice when speaking to her, but nothing seems to work. The problem I am running into is how to reprimand a skittish dog if I am trying to house-break her. I definitely don't want her to become any more scared of me than she already is, but I also don't want her to think the house is one-big toilet! How do I get her to understand right from wrong but not think I am a threat, but rather her best friend. Any advice will help tremendously!