What is the ruling on a woman uncovering her feet in front of relatives if covering them causes hardship, and do transparent socks cover the feet?

The feet are part of the 'awrah (parts of the body that must be covered) that a woman must conceal from non-mahram (definition) men, whether by wearing socks or by lengthening her garment to cover them. This is based on the Prophet's (peace and blessings be upon him) saying to Umm Salamah: "They should lengthen it by a cubit, and not exceed that." A woman must also avoid allowing non-mahram men into her home without restriction, based on the Prophet's (peace and blessings be upon him) saying: "Beware of entering upon women," especially non-mahram relatives like the husband's brother (al-hamu), who is likened to death.