What does fortune telling mean?

What does the fortune teller mean by "Kun Sui"?

You are wrong:

Kun Zao, not Kun years old.

Kun is one of the eight diagrams, a kind of yin divination, which represents a woman and her old mother, so in numerology, Kun Zao is used to represent a woman's life.

In the same way, Gangua is Yang, representing a man and a father, so Gangua represents a man's life in numerology.