Olivia Leblonk’s 17-month-old son Gabriel died in hospital after a 10-hour fight for survival.
Gabriel was hastily baptised just before he died.
Olivia told the Daily Mail: “I had him in my arms when I heard a sound of gunfire followed by flash of light like lightning.
“I looked at my child and his eyes returned my look. I screamed. He had been wounded in the back of the head.”
Liege killed four people during his attack in the busy Place Saint Lambert, in Belgium on Tuesday.
Two teenage boys and a 75-year-old woman also died in the attacks.
Olivia, who was also with her husband, Romuald was visiting a nearby Christmas market.
Gabriel was hit with a bullet from a military style assault rifle in the head close to his neck.
Amrani injured a further 122 people before killing himself. The body of a woman – believed to be his neighbour’s cleaner – was later found at his home.
Today home photos of weapons and a cannabis farm belonging to Amrani were revealed, showing a cache of guns and military-style clothing.
Amrani was know to be a “gun freak”, police have said.