If a woman wants to hasten (to leave Mina), there is nothing wrong with her appointing a proxy to stone the Jamaraat on her behalf, because of the severity of the crowding
Question

                Some men fear for their wives because of the severity of the overcrowding when stoning the Jamaraat, so they come with them to the Jamaraat, and if there is too much crowding at the Jamaraat, they stone them on their behalf, but if there is not much crowding, the women stone the Jamaraat themselves. Is it valid for them to stone the Jamaraat if the crowding is not severe, or is it acceptable for the men to stone them on their behalf if it is too crowded?
Praise be to Allah.
    Because this crowding is inevitable on 
    days like the twelfth (of Dhu’l-Hijjah), and people may want to hasten (to 
    leave Mina), and it is not possible for them to delay it until the crowds 
    become less, then there is nothing wrong with the woman appointing a proxy. 
    In fact it may be essential for her to appoint a proxy in a situation such 
    as this, because joining the crowd will undoubtedly pose a danger to her. 

    But on other days, it is possible to delay 
    stoning the Jamaraat until the end of the night, and it will be easier. End 
    quote.