Most of the current grand religious authorities (maraje') are of the view that the permission of a virgin girl's father or paternal grandfather is necessary. However, if a girl is not virgin or his father and grandfather have died, she does not need to obtain anyone else's permission.
Most of the religious authorities are of the view that the permission of a virgin girl's father or paternal grandfather is mandatory. However, if a girl is not virgin or his father and grandfather have died, she does not need to obtain anyone else's permission.
Imam Khomeini (r.a) and Ayatollah Sistani say: "A girl who has attained the age of puberty and is mature (she discerns her interest) and virgin should obtain her father or paternal grandfather's permission for marriage. In the absence of her father and paternal grandfather, she does not need anyone else's permission.
Grand Maraje' (religious authorities) such as Ayatollah Khamenei, Fazel Lankarani, Saafi, Makarem Shirazi, Wahid Khurasani and Tabrizi say: "The girl should, as an obligatory precaution, obtain her father or paternal grandfather's permission."
Grand Ayatollah Bahjat says: "Permission is necessary, as an obligatory (taklifi) precaution." And if the girl's father or paternal grandfather is absent in a way such that she does not have access to them and that marriage is necessary for her and she might suffer a harm or difficulty, their permission is not required. Similarly, if a girl's father or paternal grandfather denies her permission to marry with a man who is considered to be her 'equal' (kufw), despite the availability of all conditions and requirements and she is also interested in the marriage which is in her best interest, she can take action for marriage in the availability of the conditions.
According to Ayatollah Noori Hamedani, marriage without the permission of a girl's guardian is invalid. In case, the marriage contract has been concluded without the permission of the guardian and the guardian gives his consent later, the marriage contract would be in order. In case, he does not give his consent, the marriage contract is void (batil).
As you can see, some of the jurists do not consider a girl's being "mature" as sufficient but there are some other jurists who consider it as sufficient.
A mature girl is one who discerns her good and bad (interest) and takes decision without the effect and influence of her emotions and sexual excitements. She is mindful of her future, family and status. However, a girl who is not mature and cannot decide on her own for her future and also does not know what is in her best interest, she is not mature and she cannot marry without the permission of her father or paternal grandfather even though she might be at a high age.
It should be noted that most of the jurists are unanimous that if a girl's father or paternal grandfather are absent in the sense that it is not possible for her to get their permission, and the girl needs to marry or there is a suitable person who is religiously and conventionally considered to be her 'equal' and her father or paternal grandfather denies her permission without a valid reason, it is not necessary for her to obtain her father or paternal grandfather's permission., 
For further information, see index: 695, (Temporary Marriage, the Best Solution).
 - This passage implies that acquiring permission is a taklifi (prescriptive) as well as wadh'ei is a condition. That is to say, the marriage contract would be haram and batil.
 - Sistani: and is independent in the affairs of her life.
 - Tawzihul Masail of Maraje', vol.2, pg.287, issue No.2276
 - Ibid.
 - Ibid.
 - Ibid, issue No.2277
 - Fazel, Noori, Bahjat, Sistani, Makarem, See: Ibid
 - Ibid, issue No.2277.
 - Extracted from question 610 (Temporary Marriage with a Virgin Girl).