Kimberly Martines was separated from her husband and desperate to lure him back into her life, so police say she hatched a plan to get his attention: one that began with poisoning her 17-month-old daughter, Peyton.

She didn't use a household cleaner or pop open a bottle of pain medication, police told NBC affiliate WYFF. Instead, Martines, of Spartanburg, S.C., turned to a simple condiment found in almost any dining room: salt.

Solicitor Barry Barnette said Martines, 23, told investigators that she fed her baby a tablespoon of salt and "then had her follow through with a drink after that," according to CBS affiliate WSPA.

"She basically did that to try and get her husband's attention - to get him back into her life," the prosecutor added.

Speaking to a reporter after a recent court hearing, Martines' sister, Tiffany Lizar, disputed Barnette's claim.

"She was a great mother," Lizar told WYFF. "She would've never done anything to hurt her kids at all. There's a lot more that went on than people understand. No one should judge her at all, and there's nothing in this world that would make her hurt her babies."

Martines told police that she was awakened by the sounds of Peyton screaming Sunday, according to the Associated Press.

The child was hospitalized the same day and suffered from seizures and a high fever, AP reported.

Doctors diagnosed Martines with acute salt poisoning, according to Fox Affiliate WHNS.

Two days after she arrived at the hospital, the baby was unresponsive, prompting doctors to place her on life support, the station reported. On Wednesday afternoon, the brain dead child was taken off life support, Spartanburg County Coroner Rusty Clevenger told AP.

After originally charging Martines with felony child abuse, authorities have upgraded the mother's charge to homicide by child abuse, AP reported.

If convicted, she faces up to 20 years in prison.

Martines' two other children, one of whom is Peyton's twin, have been placed in protective custody, police told the AP.

A statement released by family members recalled the joy the infant had brought her loved ones.

"Peyton was the most beautiful, happiest, loving baby ever, the statement said. "She never cried and was a silly baby making everyone laugh. You could not help but smile when you was around her. She was a little diva who loved her nails done and her favorite thing ever was Minnie Mouse . . . Her presence will always be with us . . ."

The National Capital Poison Center writes on its website that there's no shortage of horror stories surrounding people consuming large amounts of salt, including a shipwrecked man who drank salt water and a 19-year-old who ended up in a coma two hours after drinking a quart of soy sauce.

The teen survived, the center claims, but notes that infants, people with developmental delays or dementia might not be so lucky:

"When there's too much sodium in the bloodstream, water rushes out of our cells to dilute it," the NPCC writes. "That's damaging to most cells; it's devastating to brain cells. As they shrink, they're torn away from their usual locations. Torn blood vessels and fluid build up in the brain cause seizures and coma. Fluid can build up in the lungs, causing trouble breathing. Other symptoms include intense thirst, nausea, vomiting, and weakness. Kidney damage also occurs.

David Brancati, an emergency physician in Greenville, S.C., told WHNS that in some cases even small amounts of sodium can have dangerous consequences.

"Depending on the size and the underlying medical conditions, it should not cause a life-threatening problem in a 17-month old," Brancati said, referring to Martines consuming a tablespoon of salt. "But again, there are some cases in the literature where even low amounts of sodium consumption have resulted in really bad outcomes."

"It causes an imbalance of the electrolytes in her body, and then what happens is that fluid can shift," he added. For example, people that take too much sodium, "they can have swelling of their brain, they can develop seizures, they can have arrhythmia of the heart."