Mystery as Nashville mother charged with drowning daughter, 7, 'because she was fed up of her' suffers horror injury in prison

A Nashville mother charged with drowning her seven-year-old daughter 'because she wanted to be left alone' has suffered a horrific injury in prison.

Brandi Elliott, 33, was locked up in Sumner County Jail without bond while waiting to face first-degree murder charges for allegedly drowning her daughter, Piper, in Drakes Creek in Hendersonville.

But over the weekend, she was rushed to the hospital with a severe head injury, News Channel 5 reports.

The jail has only confirmed that she was not attacked by another inmate, however it remains unclear whether Elliott was on suicide watch or if she deliberately injured herself.

She has previously claimed she had mental health issues when she made her first court appearance last month.

'When my daughter was two, I kind of lost it like I did this time,' Elliott said in court.

'I had postpartum depression and they gave me medicine for it. I was having a really bad time with sleeping.'

The mother also cried during the hearing as she told a judge that her veteran husband was living with a disability.

Yet both her attorney and state prosecutors said that they did not want her mentally evaluated.

She has had no prior criminal history and worked at McDonald's.

But on July 13, Elliott decided to take Piper to a shallow area at Drake's Creek, and held her underwater until bubbles emerged.

She allegedly told the child to be quiet as she held her under water 'like a largemouth bass,' WKRN reports.

When police later questioned her about her daughter's death, Elliott reportedly told officers she was having a bad day and Piper would not give her 'time alone.' 

Still, the mother reportedly said she only realized what she had done after it was too late and first responders tried to revive Piper with CPR. 

Police said the family are now witnesses in the probe, and have started a memorial along the greenway for Piper, which they want to turn into 'Piper’s Pathway.'

Prosecutors have said they are considering the death penalty for Elliot if she is convicted. 

Meanwhile, a GoFundMe has been set up for Piper's father, Jon Elliott. 

'Jon will be needing as many donations as possible for the funeral arrangements, and basic everyday needs, he only get a small disability check each month,' it says.

Jon, who served in Iraq, also posted a tribute to Piper online, writing: 'I will miss my baby girl forever.'