Is it permissible to change the wording of a remembrance (dhikr) from masculine to feminine, such as saying "O Allah, I am Your female servant (amatuk)" instead of "O Allah, I am Your male servant (abduk)"?

It is permissible to change the pronouns in supplications from masculine to feminine, and from singular to plural or dual, in order to make the words of the supplication conform to the state of the supplicant or the person being supplicated for. Scholars have explicitly stated this in the chapter on funerals when supplicating for the deceased. Sheikh Al-Uthaymeen cited the Hadith (definition) of Ibn Mas'ud as an example of this.