From the Book of the Entourage, the wife skill is Age + Age Modifier + Class Skill. Assuming the PK marries a 17-year old daughter of a wealthy commoner, her Lady skill is 1? Am I doing the math correctly?

Also, under the Father's Status Modifier, it says: "These will never change, whereas Age, and Age Modifiers (above) will. What does this mean exactly? When the wife ages, her modifier also changes thus increasing her skill? Or does she follow the skill progression set on Page 10, under Improvement?

once married she will progress using the improvement rule on pg.10. What it is saying about the starting modifiers is that for age the modifier will change while the modifier for the father will not change no matter how old she gets.

But my math is correct? She will start with a Lady skill of 1?

Oh yeh definitely she will start at a skill of one.