There is no blame upon them [i.e., women] concerning their fathers or their sons or their brothers or their brothers' sons or their sisters' sons or their women or those their right hands possess [i.e., slaves].1 And fear Allāh. Indeed Allāh is ever, over all things, Witness.
Translation: Saheeh International (English)
1 It is permissible for a woman to appear before these people without complete covering and to be alone with them. The brothers of both parents (uncles) are included as "fathers" or "parents," according to ḥadīth.
There is no sin on the wives of the Messenger if their fathers, sons, brothers, nephews, from lineage or breast feeding, see them and talk to them without a veil. And there is no sin on them if believing women or the servants they possess talk to them without a veil. O believing women! Be mindful of Allah in whatever He (may He be glorified) has commanded you to do and prohibited you from, because He is Watchful over what you do.