Conditions which must be met by a mahram in order to travel with him, and for there to be no khulwah
Question

                My question is that is Mahram subject to age? I. E. after a certain age (say 0 to 9,10 or 70s and 80s ect) is conditions of mahram applicable? What is the ruling on Mahram when Janazas are concern? (I.e. visiting a Janaza ect)Is same conditions applicable? Please explain?
Praise be to Allah.
    This question covers three topics: 

    1 – The age at which a person is considered to be a valid 
    mahram for a woman: 

    It was said that with regard to the mahram with whom a woman 
    may travel, he should be a Muslim, male, an adult and of sound mind, and 
    someone whom a woman is permanently forbidden to marry, such as her father, 
    brother, paternal uncle, brother through breast-feeding (radaa’ah), 
    father-in-law, etc. 
2-
    With regard to being 
    alone with a non-mahram woman (khulwah) (inside the city, i.e., not 
    traveling), this is avoided by the presence of an adult mahram or an adult 
    in front of whom they feel shy. The presence of a young child is not 
    sufficient. Khulwah may also be avoided by the presence of another woman or 
    another man, so long as there are no grounds for suspicion and there is no 
    fear of danger. 

    (al-Fataawa al-Jaami’a li’l-Mar’ah, 3/935, 938) 

    Al-Nawawi (may Allaah have mercy on him) said (9/109): “If a 
    man is alone with a non-mahram woman, without there being a third person 
    present, this is haraam according to the consensus of the scholars. 
    Similarly, if the person with them is one of whom they do not feel shy 
    because he is young, that does not avoid the forbidden khulwah.” 

    Shaykh Muhammad ibn Ibraaheem (may Allaah have mercy on him) 
    said: “The person through whom khulwah is avoided must be an adult; the 
    presence of a child is not sufficient. What some women think, that having a 
    child with her avoids khulwah, is mistaken thinking.” (Majmoo’ al-Fataawa, 
    10/52) 

    3- With regard to women visiting graves, the more correct of the 
    two scholarly views is that visiting graves is not permissible for women. 
    See Question no. 8198 and no.
    14522.
    We ask Allaah to keep us away from evil, visible or invisible… Ameen.