Praise be to Allaah.
Firstly:
If the mother was forced to have intercourse during Ramadan
by her husband, then she does not have to offer expiation, because of the
general meaning of the words of the Prophet (blessings and peace of Allah be
upon him): “Allaah has forgiven for me my ummah their mistakes and
forgetfulness, and what they are forced to do.” Narrated by Ibn Maajah
(2043); classed as saheeh by al-Albaani in Saheeh Ibn Maajah. But if
she went along with him willingly, then she has to make up that fast and
offer expiation.
The scholars of the Standing Committee for Issuing Fatwas
said concerning the ruling on one who has intercourse during the day in
Ramadan:
What he has to do is free a slave. If he cannot do that, then
he must fast for two consecutive months. If he cannot do that, then he must
feed sixty poor persons, giving each one a mudd of wheat, and he has to make
up a day to replace that day. As for the woman, if she did it willingly then
the ruling is the same as that for a man, but if she was forced to do it
then she does not have to do anything apart from making up that day. End
quote. Fataawa al-Lajnah al-Daa’imah (10/302).
If the expiation is required of her, you have said that she
is unable to fast; in that case it is sufficient for her to feed 60 poor
persons.
See also the answer to question number
1672 for information on the
expiation for intercourse during the day in Ramadan.
Secondly:
With regard to the father, he should have fasted two
consecutive months and made up that day on which he broke the fast by having
intercourse. As he has died and did not do that, then someone may volunteer
to fast on his behalf, and fast two consecutive months, because the Prophet
(blessings and peace of Allah be upon him) said: “Whoever dies owing any
(obligatory) fasts, his next-of-kin should make them up on his behalf.”
Narrated by Muslim (1147).
It is not permissible to divide the two months between more
than one person; rather it is stipulated that they should be fasted by one
person so that it can truly be said that he fasted two consecutive months.
Or they may give food on his behalf to one poor person for
each day.
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said:
If the deceased was obliged to fast for two consecutive
months, either one of his heirs may volunteer to fast them on his behalf, or
they may feed one poor person for each day. End quote.
Al-Sharh al-Mumti’ (6/453).
And he said:
It is proven from the Prophet (blessings and peace of Allah
be upon him) that if a person died owing an obligatory fast of Ramadan or a
vow or expiation, then his next of kin may fast on his behalf –i.e., if he
wishes. End quote.
Fataawa Noor ‘ala al-Darb,
20/199
Shaykh al-Sa’di (may Allah have mercy on him) said:
If a person dies owing days to be made up from Ramadan, and
he recovered from the sickness (that prevented him from fasting) and did not
fast them, then one poor person must be fed on his behalf every day, for a
number of days equal to the number of days that he owed.
According to Shaykh Taqiy al-Deen [Ibn Taymiyah], if someone
fasts it on his behalf, that is also acceptable. End quote. Irshaad
Ooli’l-Basaa’ir wa’l-Albaab, p. 79
This food for the poor must be paid for from the estate. If
someone donates it from his own wealth, there is nothing wrong with that.
And Allah knows best.