Jones himself said he had "always considered" Miss Skene as his mother.
Bowie, who died on January 10 aged 69 after losing a secret battle against cancer, also left £1.4million (NZD $3 million) to his former assistant, Corinne 'Coco' Schwab.
Miss Schwab answered a newspaper advert to be a Girl Friday in Bowie's office in 1973 and worked with him for more than 40 years.
Bowie came to regard Miss Schwab as his best friend and credited her with saving his life. Their close relationship gave rise to speculation that they were lovers.
Bowie left an estate worth £70million. Half goes to his wife Iman, who he married in 1992, and the rest is split between their 15-year-old daughter Alexandria and Duncan, 44.
Patrick Grafton Green, the London-based lawyer listed as an executor on the will, said it was 'possible' that Bowie's fortune was more than £70million (NZD $153 million).
He said: "He was very careful to ensure his [intellectual property] rights were protected."
Bowie stipulated in his will that his ashes be scattered in Bali in accordance with Buddhist rituals.
- Daily Mail