In regard to your question as to whether it is permissible to substitute the plural pronoun for the singular, the Guardian would strongly urge your N.S.A. to inform the friends to strictly adhere to the text of the Holy Writings, and not to deviate even a hairbreadth from what has been revealed by the Holy Pen.

With respect to your question as to whether it is permissible for a female in reciting the Long Obligatory Prayer to say, "I am Thy handmaiden, O my Lord, and the daughter of Thy handmaiden", you are correct in your understanding that the Guardian did not wish Bahá’ís to change the gender of pronouns and nouns in the revealed prayers. The following excerpt from a letter dated 14 January 1947 written on his behalf makes this clear:" 'In regard to the question you asked him: As Bahá’u’lláh Himself specified, in the long prayer for the dead, that the gender could be changed and "his" said for "her", etc., it is permissible to do it - nay obligatory - but in all other prayers, including those for the dead, we must adhere to the exact text and not change the gender.' "The House of Justice does not feel it appropriate to change Shoghi Effendi's usage of certain nouns in his translations. The challenge, therefore, is to accept the use of pronouns and of certain nouns such as "son" and "servant" in their generic sense, which will lead one to view the matter in terms of a spiritual response, rather than one of semantics."