Questioned by prosecutor Jane Carpenter to explain a duty-free transaction for £69.71 in New York in June 2010, Elisabetta Grillo said: "It was cigarettes for the children. I bought them and Nigella allowed me to buy them.
"I don't remember how many packs. Nigella always told me to buy it."
Asked by Ms Carpenter: "What on earth did you think you were doing, buying cigarettes for underage children?"
Grillo said: "Well, if Nigella Lawson let the children smoke weed..."
Celebrity cook Nigella Lawson said she was "disappointed but unsurprised" after her two former personal assistants were cleared of fraud.
The revelations that emerged in the fraud trial of two former aides to Nigella Lawson are unlikely to damage the TV chef's meteoric career.
Nigella "let the children smoke weed," an ex-PA has alleged, admitting she had wanted to drop drug claims out of sympathy for her ex-boss.