What ！an incorrect Taijiquan bad for us?

part from the ASK CTM by AINing
My daughter talked to a Taijiquan practitioner, whose Taijiquan is a family transmission. My daughter played a set of Tai Chi to show him, he said, you this is tai Chi exercise, not tai Chiquan. My daughter refused to accept, because her's Taijiquan was specially trained, and had participated in the competition. The master said, "If you do tai Chi like this, you will get ill and feel cold limbs."

I was shocked, he is right, my daughter really limbs cold nearly two years, always says hands cold, when I was pregnant with her and did not catch cold, she was warm in childhood. how is this cold to come from? Unexpectedly, it was just because to take part in the competition. I don't understand. Even if it is not tai Chi KongFu, is tai Chi exercises, also not to help the body, but brings harm, can simple exercise will bring harm to health?