A Buddhist once said that a bodhisattva is neither male nor female and appears in whatever form is convenient.
"Buddhism and Buddhists in China"
Lewis Hodus
The bodhisattva, that is the Buddha to-be, resides in the Tusita Heaven and selects his birth-place and parentage.
"Hinduism and Buddhism, Vol I. (of 3) An Historical Sketch"
Charles Eliot
The object of these biographies is less to give information about previous Buddhas than to trace the career of Gotama as a bodhisattva.
"Hinduism and Buddhism, Vol I. (of 3) An Historical Sketch"
Charles Eliot