The woman, who had an elastic band and hair bobble on her wrist, is thought to have been in the water for one or two months before she was discovered.
Police believe she may have entered the water in a surrounding area or region, with the River Tame and River Goyt both merging into the River Mersey.
Her cause of death is being treated as unexplained and further analysis of her body is due to be completed.
DI Edwards said she could be “someone’s mother, auntie, sister, or cousin,” adding that “somebody out there will know who she is”.
She has urged anyone with any information to come forward as even the “smallest detail” could help establish her identity.
