Watson is a YA historical fiction writer, mostly about the British royals. She moved to England in 1964 and lived there for 24 years. Her most well-known works are parts of her English Family Tree series. Most of her books went out of print in the 1970s, many eventually reprinted by Image Cascade. She has also written YA novels set in ancient Egypt. Her most recent book is The Angry Earth, an adult story of the New Madrid earthquakes of 1811.