Antonio Santiago died of a gunshot wound last Thursday after a botched robbery by two teenagers.
Mum Sherry West was out for a walk in the historic city of Brunswick, Georgia, US, when she was approached by the teens.
She said one 'asked me for money and I said I didn't have it'.
She added: "When you have a baby, you spend all your money on babies. They're expensive. And he kept asking and I just said 'I don't have it'. And he said, 'Do you want me to kill your baby?' And I said, 'No, don't kill my baby'."
Authorities said one of the teens fired four shots, grazing the mother's ear and striking her in the leg, before he walked around to the stroller and shot the baby in the face.
De'Marquis Elkins, 17, is charged as an adult with first-degree murder, along with a 14-year-old who was not identified because he is a juvenile.
Sherry said her son was walking well on his own and eight of his teeth had come in. But she also mourned the milestones that will never come, like Antonio's first day at school.
"I'm always going to wonder what his first word would be," she said.
Tragically, Sherry also lost her teenage son five years ago when he was stabbed to death in a fight.
Shaun Glassey, 18, was killed with a steak knife during an attack involving several other teenagers on a dark street corner in Gloucester County, New Jersey.