How could one say Yes? for years and years

Hi,
Here are some words from the novel Lady Chatterley's Lover（page 64, Chapter Five) by DH Lawrence (planetebook):
(background: Clifford and Connie were going around in their wood. Clifford suggested Connie have a son with another man，who should be from upper-class. Connie hesitated: go on weaving herself into his life all the rest of her life? Nothing else?……）

Quote:

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Was it just that? She was to be content to weave a steady life with him, all one fabric, but perhaps brocaded with the occasional flower of an adventure.

But how could she know what she would feel next year? How could one(=I/Connie) ever know? How could one(=I/Connie?) say Yes? for years and years? The little yes, gone on a breath!

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How should I understand the blue sentence please? Does the one refer to Connie herself?
I take it to be how could I say: "Yes, (I love you) for years and years"

Is that possible?
Thank you in advance

I understand it that way:"How could I conform to his wishes during all these years?"

Thank you. Sounds reasonable. But why did Lawrence use she in the previous sentence, but used one in this sentence?

You yourself market it out. In the previous sentence it´s a third person narrator that is referring to Connie´s feelings from the outside. Then he sort of enters into Connie´s head and speaks with her own voice.

Really thank you. I get it