As someone who just finished reading her book City of Illusions, this is a fun coincidence. The first chapter of (her interpretation of) the Tao Te Ching features in the book, and the bit about "two things, one origin, but different in name" is a central aspect of the book.

City of Illusions is one of her earlier works, but I found it a great read, and definitely could see the throughline to The Left Hand of Darkness, which would be published a couple years later.