Her family forced her to break her fast because she was sick – were they sinning? Can she fast if she wants to?
Question

                My maternal aunt had an accident when she was young and lost one of her eyes, and the doctors decided that this child should not cry or get hungry, because that may affect her remaining eye. So her father would not let her fast when fasting became obligatory for her, based on the doctor’s report. She is a woman who is deeply religiously committed, and after she got married she thought that fasting would not affect her, so she fasted. 

My question is: Now she fasts most of the days (of Ramadaan) so that her father would not be punished, for she loved her father very much (may Allaah have mercy on him) and she wants to ask you: did her parents do anything haraam? Does she have to fast all the months that she missed?.
Praise be to Allah.
    Sickness is one of the excuses which make it permissible not 
    to fast. Allaah says (interpretation of the meaning):  

    “and whoever is ill or on a journey, the same number [of 
    days which one did not observe Sawm (fasts) must be made up] from other 
    days”

    [al-Baqarah 2:185]

    The ruling on a sick person fasting is that it is either 
    makrooh or haraam. It is makrooh if fasting is difficult for him when he is 
    sick, and it is haraam if fasting will harm him. 

    For more information on this, please see question no.
    50555 and
    38532. 

    A sick person should not stop fasting unless a trustworthy 
    doctor who specializes in that disease testifies that he should do so; some 
    scholars stipulated that the doctor should also be a Muslim. 

    If a person does not fast on the advice of a doctor, there is 
    no sin on him. If it is a chronic – permanent – disease then he may not fast 
    and he should feed one poor person for each day. If it is a temporary 
    sickness, then he may break the fast and make it up after he recovers. 

    Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allaah have mercy on him) 
    said: 

    If specialist doctors determine that this sickness of yours 
    is one for which there is no hope of a cure, then you must feed one poor 
    person for every day of Ramadaan, and you do not have to fast. The measure 
    of that (food to be given) is half a saa’ of the local staple food, whether 
    it is dates, rice or something else. If you invite a poor person for a meal, 
    lunch or dinner, that is sufficient. But if the doctor determines that there 
    is hope for recovery from your sickness, then you do not have to feed a poor 
    person, rather you have  to make up the missed fasts when Allaah grants you 
    healing from that disease, because Allaah says (interpretation of the 
    meaning):  

    “and whoever is ill or on a journey, the same number [of 
    days which one did not observe Sawm (fasts) must be made up] from other 
    days”

    [al-Baqarah 2:185]

    I ask Allaah to bless you with healing from all ills and to 
    make what has befallen you a purification and an expiation from sin, and to 
    enable you to be patient and seek reward, for He is the best One to be 
    asked. End quote. 

    Fataawa al-Shaykh Ibn Baaz 
    (15/221). 

    It seems to us from the question that the father of the sick 
    woman did not commit any sin, because he only kept her from fasting on the 
    basis of medical advice. 

    The scholars of the Standing Committee for Issuing Fatwas 
    were asked: 

    I fell sick with kidney disease and I had two operations. The 
    doctors advised me to drink water night and day, no less than two and a half 
    litres every day. They also told me that fasting and refraining from 
    drinking water for three consecutive hours would expose me to danger. Should 
    I follow their advice, or should I put my trust in Allaah and fast, even 
    though they told me that I have the potential to develop kidney stones? Or 
    what should I do? If I do not fast, what is the expiation I have to give? 

    They replied: 

    If the matter is as you described, and these doctors are 
    highly skilled in medicine, then what is prescribed is for you not to fast, 
    so as to protect your health and ward off harm from yourself. Then if you 
    recover and are able to make up the fasts without any hardship, you have to 
    make them up, but if the sickness that has befallen you continues or there 
    is the danger of your developing kidney stones if you do not continually 
    drink water, and the doctors have determined that there is no hope of 
    recovery from that, then you have to feed one poor person for every day that 
    you do not fast. End quote. 

    Shaykh ‘Abd al-‘Azeez ibn Baaz, Shaykh ‘Abd al-Razzaaq 
    ‘Afeefi, Shaykh ‘Abd-Allaah ibn Ghadyaan, Shaykh ‘Abd-Allaah ibn Munay’. 

    Fataawa al-Lajnah al-Daa’imah 
    (10/179, 180) 

    If the sister who is sick feels that she is able to fast 
    without that affecting her eye, then there is nothing wrong with her 
    fasting, but she should do that in consultation with trustworthy doctors, 
    lest she be deceived by her appearing to be well, but that fasting affects 
    the health of her eye. 

    As for her making up the days that she did not fast in the 
    past, it seems that she does not have to do that, and it is sufficient for 
    her to feed one poor person for every day, because she refrained from 
    fasting on the basis of medical advice. 

    Shaykh Ibn Baaz (may Allaah have mercy on him) was asked 
    about a person who was affected by a chronic disease and the doctors advised 
    him never to fast, but he consulted doctors in another country and was 
    healed by Allaah’s leave. Five Ramadaans have passed and he did not fast. 
    What should he do after Allaah has healed him? Should he make them up or 
    not?  

    He replied: 

    If the doctors who advised him never to fast were Muslims, 
    trustworthy and familiar with this sickness, and they told him that there 
    was no hope of recovery for him, then he does not have to make it up, and it 
    is sufficient for him to feed poor persons (one for every day missed), but 
    he has to fast in the future. 

    Fataawa al-Shaykh Ibn Baaz 
    (15/355). 

    To sum up: 

    There is no sin on her parents for what they did by making 
    their daughter not fast on the basis of medical advice, but she has to pay 
    the fidyah (ransom) by feeding one poor person for every day that she did 
    not fast after she reached puberty. If trustworthy, specialist doctors 
    determine that she is able to fast now, with no hardship or fear of harm, 
    then she must fast Ramadaan, and she has no excuse for not fasting. And if 
    she wants to observe voluntary fasts then there is nothing wrong with that. 

    And Allaah knows best.