I don't think she had first hand knowledge of Chinese family life. I think American thought she did.
Hard to say, exactly. She was born in 1892 and lived most of her life in China until 1934. Most Chinese critics have praised her work for its realism in portraying peasants.
I should add that, IIRC, her husband was intimately involved in the University of Nanking project that gave the first accurate demographic and sociological description of Chinese peasant households. And she saw a bit too much of the Nanking Revolt.
She wasn't a member of a Chinese family so she couldn't have had, strictly speaking, first hand knowledge. But she was well acquainted with Chinese family life.
If you were truly snarky, you would have done the "thread closed" bit.
The Good Earth was summer reading after my freshman year of H.S. and I became obsessed with the book, reading it at least three times. Many years later I read Wild Swans: Three Daughters of the Revolution and was struck by the parallels in the descriptions of the grandmother's household.
So I live in America. It doesn't make me an expert on the poor.
Pearl Buck was a big celebrity in her day, and is almost forgotten now.
R4=Wang Lung's third cousin once removed.
She wrote of Chinese families as an observer, not a participant.