When a chi comes from a place that they were on carpeting all the time, the plain wooden floor is very scary. Work with her, ie, toss tiny bits of something delicious on the floor just beyond the carpet. She will stretch to get it. Then move the treat by inches, until she has to leave the carpet entirely. Slowly does it. May take a week or more. Don't rush it.
(a short story: my brother and I were adopted at 19 months of age. We were in a nursery with linoleum flooring. When we came home, we were terrified of rugs! Took awhile before my Mom and Dad could put us down without screaming!)