Can the washing of the deceased be attended by one who does not need to be there?
Question

                Is it permissible for the washing of the deceased to be attended by one who does not need to be there?.
Praise be to Allah.
    Ibn Qudaamah (may Allah have mercy on him) said: It is 
    makrooh for anyone other than the one who is washing the deceased and those 
    who are helping him to attend the washing of the deceased, because it is 
    makrooh to look at the deceased except if there is a reason, and it is 
    mustahabb for those present to avert their gaze from him unless there is a 
    reason to look at him. The reason for that is that there may be in the 
    deceased a defect that he was concealing and that he would not like people 
    to see or know about after his death, or there may be some issues that a 
    living person would not like people to see or know about. And there may 
    appear something that may indicate something objectionable and he may tell 
    others about it, which is like exposing the deceased to scandal. And his 
    ‘awrah may become uncovered and be seen. Hence we prefer for the one who 
    washes the deceased to be trustworthy and righteous, so that he will conceal 
    anything that he may see.

    End quote from al-Mughni, 2/164 

    An-Nawawi (may Allah have mercy on him) said: It is mustahabb 
    to transfer him to a private place and conceal him from people’s gaze. There 
    was no scholarly difference of opinion concerning this.

    End quote from Sharh al-Muhadhdhab, 5/125 

    There is no particular limit to the number of people who may 
    be present; rather it is limited to what is needed. If there is an urgent 
    need for more than one person, there is nothing wrong with that. This is 
    indicated by the report narrated by Umm ‘Atiyyah (may Allah be pleased with 
    her) who said: The Messenger of Allah (blessings and peace of Allah be upon 
    him) entered upon us when his daughter died and said: Wash her three times 
    or five times or more than that if you see fit, with water and lotus leaves, 
    and put camphor or a little camphor in the last time. Then when you have 
    finished call me.” Them when we had finished we called him… 

    Narrated by al-Bukhaari. 1253; Muslim, 939 

    But some of the scholars (may Allah have mercy on them) made 
    an exception for the next of kin of the deceased and said that he may be 
    present even if there is no need for him to be there, out of compassion 
    towards the deceased. 

    An-Nawawi (may Allah have mercy on him) said: Our companions 
    said: it is mustahabb for no one to be present except the one who is washing 
    him and whoever is needed to help him in washing. Our companions said: and 
    the next of kin may enter, even if he does not wash him and does not help.

    End quote from Sharh al-Muhadhdhab, 5/125 

    al-Qaadi and Ibn ‘Aqeel among the Hanbalis said: And that is 
    not unlikely. End quote from al-Insaaf, 2/486. 

    Shaykh Muhammad al-Mukhtaar ash-Shanqeeti (may Allah preserve 
    him) said: Some of the scholars granted a concession allowing some of the 
    relatives (to be present) out of compassion, such as if it is his son and he 
    wants to be present to wash him, and that may apply to some of the relatives 
    so that it will help them to accept the decree of Allah, may He be glorified 
    and exalted, because they may see signs that are indicative of good and that 
    will help the relatives to be patient. And this is something well known; 
    perhaps they will wash him and will see good signs whilst washing him, so 
    that will help his relatives to be patient and seek reward with Allah for 
    their loss.

    End quote from Sharh az-Zaad. 

    And Allah knows best.