Eris had been born pregnant, and after 55 years (Goddesses have an unusually long gestation period -- longer even than elephants),
That is short pregnancy when compared to Ilmatar from Finnish mythology. She was an air goddess who fell from the sky and who was impregnated by the air and the sea. She floated for 730 years unable to give birth until there was land. Her son, Vainmoinen, was born an old man, with all the wisdom of the ages.