It's almost impossible to separate Theodora Kroeber from her most acclaimed accomplishment, which was writing the biography of Ishi, the last man of the Yahi Tribe of California. If you read it, you would think she was an intricate part of Ishi's last years, during which he lived in the Museum of Anthropology at Berkeley.
Yup, you read that right: he lived in the museum, teaching the scientists about his lost culture and doing demonstrations of his craft for families.
But in reality, she wrote the entire biography from a second-hand source: her husband. He was the one who worked closely with Ishi upon his discovery in 1911 until his death in 1916, but he couldn't write the book because he was too close, too personally attached, to be clinical about it at all.
So Theodora took the reins…and she nailed it.
While all this was going on, Ursula was still a young author, and seeing her mother become such a success in a field where women rarely tread had a huge influence on her. While being interviewed in The Paris Review, Le Guin talked about her mother's impact:
My mother had always wanted to write. She told me this only after she'd started writing. She waited until she got the kids out of the house, until she was free of responsibility for anybody except her husband. Very typical of her generation. She was in her fifties when she started writing—for kids, which is how women often start. It's not threatening to anybody, including themselves. And she published a couple of lovely little kids' books.
She wanted to write novels, and she did write a couple, but they never found a publisher. But what happened was that she got asked to write the biography of Ishi. Of course they asked my father and he said, No way, I cannot handle that story. He'd lived that story and didn't want to write it. He wasn't a reminiscer. He said, I think you might ask my wife, she's a good writer. And they did, and she did it. So her first published adult book was a best seller, which was wonderful for her! She was in her sixties then. (Source)
Her mom was also the first person to expose Ursula to feminism through Virginia Woolf, and we all know how large a part of her life that became. Theodora gave her A Room of One's Own as a teenager, which Le Guin refers to as a "thoroughly corrupting" experience (jokingly, of course).
So, it was her mother who taught her many of the feminist fundamentals that Ursula expanded upon and made her own through her literature and speeches like her Left-Handed Address, and influenced her in innumerable other ways, as well. What an awesome mom.