When does a woman in a state of ihram who is experiencing menstruation change her ihram, and what are her duties and prohibitions, and is she allowed to appoint someone to cast the jamarat on her behalf?

A female in ihram may change her clothes as long as they are not perfumed. The state of ihram ends for the mutamir (one performing 'Umrah) after shaving or shortening her hair. For the hajji (one performing Hajj), there are two stages of tahallul (exiting the state of ihram): The first is after performing two out of three rituals (stoning Jamarat al-Aqabah, shaving/shortening the hair, and Tawaf al-Ifadah with Sa'y), whereupon everything becomes permissible for her except intimacy with her husband. The second is after performing the third ritual, whereupon intimacy with her husband also becomes permissible for her. The pillars of Hajj are five: Ihram, Tawaf, Sa'y, Standing at 'Arafah, and shaving/shortening the hair (according to some). Hajj is not valid without them. The wajibats (obligatory acts) of Hajj are: Entering ihram from the miqat, standing at 'Arafah for part of the night, spending the night at Muzdalifah and Mina, stoning the jamarat, shaving/shortening the hair, and Tawaf al-Wada' (farewell circumambulation). Whoever intentionally misses a wajib is sinful and must offer a dam (sacrificial animal). Whoever misses it unintentionally is not sinful, her Hajj is valid, and she must offer a dam. The prohibitions of ihram for a woman are the same as for a man, except that she covers her head and her entire body, excluding her face and palms, and she lets down a covering over her face when men pass by. It is forbidden for those in ihram to: use perfume, cut hair, trim nails, hunt, engage in sexual intercourse or its مقدمات (preliminaries), and contract marriage. Stoning the jamarat is obligatory for a woman to do herself, unless she is unable, in which case she may appoint someone to do it for her.