Isabel Estrada, a mother of eight from the village of Izucar de Matamoros in the central Mexican state of Puebla, was finding it hard to conceal an almost childlike delight when the governor of the state handed over the keys to her new house on Saturday.

The small house, in a modern development in the long shadow of the volcano Popocatapetl, was a gift from two of her sons, who have lived and worked as waiters in the US for the past seven years.