Her mother died and she had vowed to sacrifice a sheep; can herdaughter give the cash value instead?

Her maternal uncle was in an accident and her mother had vowed that if
he got out safely she would sacrifice a sheep or the like, and would
invite people, neighbours and friends, or distribute the meat among
people. Praise beto Allah, her uncle got out safely, but Allah willed
that the mother should die two years ago, without having fulfilled the
vow. Is she now required to fulfil the vow on her mother'sbehalf? Can
she give money to the poor in Iraq? Please note that the daughter
lives in Europe and it is difficult for her to fulfil the vow by
slaughtering an animal.
Praise be to Allaah.
Firstly:
If a person makes a vow to sacrifice a sheep, for example, if Allah
saves his relative, this is a vow to do an act of worship which must
be fulfilled. If your mother died before fulfilling her vow,then it is
regarded as a debt that she owes and must be paid for out of her
estate. If she did not have any wealth, it is mustahabb for her
children to do it on her behalf. Al-Bukhaari (2761) and Muslim (1638)
narrated from Ibn'Abbaas (may Allah be pleased with him) that Sa'd ibn
'Ubaadah (may Allah be pleased with him) asked the Messenger of Allah
(blessings and peace of Allah be upon him): My mother died, and had
made a vow (that she did not fulfil). He said: "Fulfil it on her
behalf.
An-Nawawi (may Allah have mercy on him) said in Sharh Muslim: The
words of the Prophet (blessings and peace of Allah be upon him),
"Fulfil it on her behalf" indicate that obligationsthat were required
of the deceased should be fulfilled. With regard to financial
obligations, there is scholarly consensus (that the mustbe fulfilled).
As for obligations to do other acts of worship, there is a difference
of scholarly opinions concerning them.
Moreover, the view of ash-Shaafa'i and others is that financial
obligations that were required of the deceased, such as zakaah,
expiation and vows, must be fulfilled, whether he left instructions to
that effect or not, as is the case with debts owed to people.
It should be noted that our view and that of the majority is that the
heir is not obliged to fulfil the vow that was obligatory upon the
deceased if it was not financial, or if it was financial but he did
not leave behind any estate, but it is mustahabb for him to do that.
End quote.
Secondly:
If a person vows to sacrifice a sheep or the like, it is obligatory
for him to fulfil the vow, and it is not acceptable to pay the cash
value instead. The Standing Committee for Issuing Fatwas were asked
about a woman who vowed to sacrifice a lamb every month, but she found
it difficult to buy lambs, slaughter them and distribute the meat. Is
it permissible for her to give the cash value of the lambs?
They replied:
There is no hardship in sacrificing lambs; rather she has to continue
sacrificing them and distributing the meat to the poor, and it is not
acceptable for her to give the cash value, because the Prophet
(blessings and peace of Allah be upon him) said: "Whoever makes a vow
to do an act of obedience to Allah, let him do it, and whoever makes a
vow to do an act of disobedience to Allah, let him not do it." End
quote.
Shaykh 'Abd al-'Azeez ibn Baaz, Shaykh 'Abdullah ibn Ghadyaan, Shaykh
'Abdullah ibn Qa'ood.
Fataawa al-Lajnah ad-Daa'imah, 23/395
Based on that, it is not permissible to give the cash value instead of
slaughtering the sheep; the fact that the questioner lives in Europe
does not mean that she cannot delegatesomeone to sacrifice a sheep and
distribute the meat to neighbours and friends, either in the country
where she is living or elsewhere.
And Allah knows best.