What is the best way to potty-train a dog?

My little doggie is a rescue dog, 2–3 years old, a long-haired chihuahua with impeccable manners. She does not whine, bark or whimper. I was told that she had been mistreated by a man because she won’t go near one, she shakes and is fearful beyond belief. I was also told that she was potty-trained.

Since coming here about a month ago, she has taken to laying little cigars (she weighs about 3.5 lbs.) right by my husband’s side of the dining room table…which has ignited horrible episodes which do nothing but make her more fearful.

I am attempting to get her outside just a few minutes after she eats…she holds it until she’s back inside.

I need help badly.