Jessica's heartbroken mother Teresa Inniello told WSB Radio that her daughter had returned home from a dinner out with her 30-year-old partner Antoine Davis.
READ: HOW TO DEAL WITH GRIEF AND SEPARATION
At some point in the evening, Davis, a former Marine who served in Iraq, became drunk and abusive - something which had happened many times before, according to Teresa.
"She was the hero, because her last breath was saving the child”
Davis chased Jessica - who was clutching their six-month-old daughter Cobie in her arms - up the stairs of their three-story townhouse.
The frightened 33-year-old tried to defend herself with a baseball bat, but she was overpowered by the former serviceman, who struck her - and baby Cobie - several times with the bat, Ionniello said.
Terrified for herself and her baby, Jessica locked herself in a bathroom.
PHOTOS: COUPLE REMEMBER STILLBORN DAUGHTER WITH EMOTIONAL PHOTOSHOOT
Davis got his gun, an assault rifle outfitted with a suppressor, burst into the bathroom and, while Jessica was still holding Cobie in her arms, shot the young mother in the head.
Teresa said: “He shot her and they (police) don’t know how she was able to twist her body and fall literally in the opposite direction."
Instead of falling onto the floor, Teresa said her daughter fell over the toilet, dropping little Cobie into the water-filled bowl and sheltering her with her body.
“She had pure will,” Teresa said. “She wanted that baby to live.”
READ: INSPIRATIONAL QUOTES ON DEALING WITH GRIEF
Cobie’s grandmother believes Davis intended to kill both mother and child, but, unable to see the child inside the toilet bowl, he left the bathroom, walked into the baby’s room and shot himself.
Devastated Teresa added: “She was the hero, because her last breath was saving the child.”
When police arrived on the scene, they feared there was a hostage situation, and didn’t want to rush in immediately and jeopardise any lives.
Little Cobie remained in the toilet, covered by her mother’s body, for 13 hours before officers finally stormed the townhouse and rescued her. She was cradled in the arms of an officer who rushed her outside to a waiting ambulance.
Cobie is still being treated at Children’s Health Care of Atlanta at Scottish Rite Hospital for a traumatic head injury.
Teresa, who is already caring for Jessica's 15-year-old daughter, Naomi, said she hopes to bring her granddaughter home to live with her soon.
**Friends have set up a fund to help look after the two children she left behind. **
So far, the fund has raised almost $20,000.
["Not all pregnancies have a happy ending": One couple reveals how to support a family if their baby dies](https://closeronline.co.uk/news-real-life/opinions/pregnancies-happy-ending-one-couple-reveals-support-family-baby-dies/ ""Not all pregnancies have a happy ending": One couple reveals how to support a family if their baby dies")