In this chapter the author wants to tell in a poetic way that the author was seeing him old from 20 yrs and he had not noticed any physical change she became old in the age of about 40 and wrinkled too.

Meaning of the sentence:
The sentence means that the speaker had known the woman for twenty years, and during that time, she had been elderly and had wrinkles on her skin.

Explanatory details:
To further understand the sentence, we can break it down into the following points:

- Duration of knowing the woman: The speaker had known the woman for twenty years. This means that the speaker has had a long-term relationship with the woman, and has had ample time to observe her physical appearance over time.

- Age of the woman: The woman was old. This implies that she was likely past middle age and had lived a long life. The use of the word "old" indicates that the woman was elderly, and that her age was noticeable.

- Physical appearance of the woman: The woman was wrinkled. This indicates that the woman's skin had lines and creases on it, which is a common sign of aging. The use of the word "wrinkled" emphasizes this aspect of the woman's appearance.

- Consistency over time: The sentence suggests that the woman's age and wrinkles were consistent over the twenty-year period during which the speaker knew her. This implies that the woman's appearance did not change significantly during that time, and that the speaker had come to expect her to look a certain way.

Overall, the sentence paints a picture of an elderly woman who had been a constant presence in the speaker's life for a long time. The use of the past perfect tense ("had been") suggests that the woman's age and wrinkles were a defining characteristic of her identity, and that they had remained unchanged over time.