Must a woman observing 'iddah cover her feet?

The feet are part of the 'awrah ( एरिया of nakedness) of a free, adult woman, whether in prayer or outside of it, in front of those to whom it is unlawful to look at her. This is based on the hadith of Umm Salamah, may Allah be pleased with her, that the Prophet, peace and blessings be upon him, said concerning women letting down their garments: "They should let them down by a span." She (Umm Salamah) said: "Then their feet will be uncovered." He said: "Then they should let them down by an arm's length and no more."