Laura Stanley, 38, was found dead near Chorlton Water Park in Manchester on 21 March last year.
She has now been named by Greater Manchester Police (GMP).
The force said a relative had contacted officers after a facial reconstruction image was released.
A DNA match was then confirmed through a familial link.
Ms Stanley was originally from Derbyshire and had been living in Stockport.
Her family said in a tribute: “Laura was a kind and gentle person with a great sense of fun and adventure.
“She was generous, thoughtful, caring and always keen to volunteer within the community.
“Laura was a proud and loving mum and she will be greatly missed by her girls and all of her friends and family who loved her dearly.”
Investigators are now trying to piece together the final movements of Ms Stanley, who is believed to have last been seen in January 2024.
Read more from Sky News:
Victims of house fire named by police
Woman who beat man to death with kettle jailed
GMP’s professional standards directorate is reviewing a missing report made before her body was discovered.
Detective Inspector Louise Edwards said: “For the last 12 months, the investigation team have worked meticulously on this case, demonstrating commitment and dedication to giving Laura her identity back and reuniting her with her family and loved ones.
“I would like to pass my condolences on to all of those who knew Laura, especially her family, who we are continuing to support at this awfully difficult time.
“We will now continue to investigate Laura’s last movements and how she ultimately came to be discovered in the River Mersey just over a year ago.
“These are answers her family deserve and we will be keeping them updated as we carry out this work.”
