She was rushed to hospital with her life hanging "in the balance", police said. Her condition has since improved but she requires ongoing treatment, the BBC reported.
Warner's son Jeffrey said the family were "sickened" by the attack.
The family have released images of Warner's injuries, including bruising to her face and down the entire length of her body, to try to find the person responsible.
It is believed Warner was attacked at some point between midday on June 2 and midday on June 4.
Ms Warner told officers she was woken by a man standing over her who she believes struck her in the face several times with some kind of instrument.
Scotland Yard said her bedroom was left in a messy state suggesting the man had searched for something, but it is not known yet if anything was stolen.
"Her family are desperate for any information from the public that could help us catch this man," he said.
Prashant Patel, who lives on Brampton Road where Warner lived, said he felt "shocked" and "horrified" by the attack.
The Indian-origin man added that he was worried for his 85-year-old mother, who he cares for, and was "scared for her when I'm not here".
The brutal attack on Warner came days after a 100-year-old woman died after suffering multiple injuries including a broken neck when her bag was stolen.
A 39-year-old man who was initially detained on suspicion of robbing her has been arrested on suspicion of her murder, Independent newspaper reported.
He remains in police custody and is being questioned. Derbyshire Police is appealing for anyone with information on the incident to come forward, it added.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)