Once a glamourous queen during her reign in Egypt, Dedyet went through a huge personality change after the de Nile family were separated during a takeover by Cleo's uncle. Separated from the rest of her family, Dedyet found herself inside a tomb, waiting for word of her family's safety. With nothing else to do, she took to reading books from the adjoining library. It was reading about ancient Egypt and how archaeologists discovered ancient artefacts and shared them with the world that inspired her to take up archaeology herself. She also lost interest in the lush lifestyle she had used to live, and felt more comfortable wearing older clothing and not bothering with styling and make up.
After finally leaving her tomb, Dedyet travelled to the Boo World to look for her family. On her travels, she came across an archaeological expedition, and offered to lend assistance, believing she would have plenty of time to find her family later. However, she and the group ended up trapped inside a tomb for several years. (In Hexiciah Steam's diary she is trapped inside the Catacombs).
Eventually, she was freed and reunited with her family, who were very surprised by her new outlook on life. But they soon discovered that she is still the kind, loving woman they remember.
Dedyet is described as looking like an older version of Cleo. She prefers to wear old, comfortable clothing such as shirts and jeans.
Dedyet is the wife of Ramses de Nile. Despite being apart for so long, the two are still very much in love, and are even seen bonding over antiques.
Dedyet's name is a play on the words "Dead Yet". Combined with 'de Nile' which sounds like 'denial' , this may be a reference to Cleo's belief that her mother has always been alive.