Is it permissible for a woman to appoint someone else to stone the Jamarat on her behalf, if the Jamarat location is far away from her?
Question

I did Hajj four years ago, and on the last day for stoning, I appointed someone else to stone the Jamarat on my behalf, because my place was far away, as the tents were 5 km away from the Jamarat. Do I have to do anything?
Praise be to Allah.Firstly: 
The basic principle is that if a person is able to stone the Jamarat for himself, it is not permissible for him to appoint someone else to stone them on his behalf. 
Shaykh Ibn Baz (may Allah have mercy on him) said:
if he is healthy, he does not have the right to appoint someone else to do it on his behalf; rather it is obligatory for him to stone them himself, because when he entered ihram for Hajj, it became binding upon him to complete it, even if it was voluntary, because starting Hajj makes it obligatory to complete it, as Allah, may He be glorified and exalted, says (interpretation of the meaning): “And perform properly (i.e. all the ceremonies according to the ways of Prophet Muhammad (blessings and peace of Allah be upon him)), the Hajj and Umrah (i.e. the pilgrimage to Makkah) for Allah” [al-Baqarah 2:196]. 
The same applies in the case of ‘umrah, as is indicated in the same verse: if a person begins it, it is obligatory for him to complete it and perfect it, and he does not have the right to delegate some of the actions of Hajj so long as he is able to do them, according to the correct view.
End quote from Silsilat al-Fataawa ash-Shar‘iyyah – Fataawa al-Hajj, compiled by Khaalid al-Juraysi (p. 107) 
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: 
It is not permissible for a woman or anyone else to delegate someone to stone the Jamarat  on her behalf, because stoning the Jamarat is one of the actions of Hajj, and Allah, may He be blessed and exalted, says (interpretation of the meaning): “And perform properly (i.e. all the ceremonies according to the ways of Prophet Muhammad (blessings and peace of Allah be upon him)), the Hajj and Umrah (i.e. the pilgrimage to Makkah) for Allah” [al-Baqarah 2:196]. 
For this reason the Prophet (blessings and peace of Allah be upon him) gave permission to the weak ones among his family to leave Muzdalifah at night so that they could reach Mina before it became crowded, and then stone Jamrat al-‘Aqabah, but he did not give them permission to appoint someone else to stone it on their behalf. Similarly, the Prophet (blessings and peace of Allah be upon him) gave permission to the camel herders to stone the Jamarat on one day and not the next, but he did not give them permission to appoint someone else to stone them on their behalf. This confirms that stoning the Jamarat must be done by the pilgrim himself (or herself). 
End quote from Majmoo‘ Fataawa Ibn ‘Uthaymeen (23/107) 
Secondly: 
If a person is unable to stone the Jamarat for a valid reason that is acceptable according to sharee‘ah, such as illness or weakness that makes him unable to bear the difficulty of stoning the Jamarat and putting up with the crowds, or because he is elderly and is not able to stone the Jamarat at all, or a pregnant woman fears for her foetus, and similar excuses, then in such cases it is permissible to appoint someone else to stone the Jamarat on one’s behalf. 
Ibn Qudaamah (may Allah have mercy on him) said: If a man is sick or detained or has a valid excuse, it is permissible for him to appoint someone to stone the Jamarat on his behalf.
End quote from al-Mughni (3/257) 
Shaykh Ibn Baz (may Allah have mercy on him) said: There is nothing wrong with appointing (someone to stone the Jamarat) on behalf of one who is sick or a woman who is unable to do it, such as one who is pregnant or heavyset or weak, and she is not able to stone the Jamarat.
 End quote from Majmoo‘ Fatawa Ibn Baz (17/301) 
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said:
if the pilgrim cannot stone the Jamarat, either because of old age, or because he is sick or because she is a pregnant woman, or because he or she is blind and will find it difficult, then in this case there is nothing wrong with appointing someone to do it on one’s behalf, because it is a case of necessity.
End quote from Majmoo‘ Fatawa Ibn ‘Uthaymeen (23/119) 
In order to evaluate cases of weakness or difficulty for one who is accountable but is not able to bear it, reference should be made to the situation of the individual and his honesty before his Lord. You know yourself best, and can compare your case to the details mentioned above. If you did that because you thought it most likely that you were too weak to bear this difficulty, or because someone whose knowledge you trust advised you to do that, then there is no blame on you for what you did, in sha Allah. 
And Allah knows best.