In continuation from here
http://hps.monkeywarrior.com/node/7109

HpS - We also remember where Prabhupada was talking about Narayani Devi Dasi and said, "Mother Narayani".   We feel it is just as respectable a title as Maharaja for a Sannyasi.  Of course, there is not restriction to say, Narayani Mataji, Prabhu, no?

~

Yes Guru Maharaja.

My humble understanding is that it is always nice and safe to address a person in female body as mataji, mother. Term mataji is particularly proper to use when addressing a lady who is unknown to us.

I have slight memory hearing that Srila Prabhupada sometimes happened to call his female disciples as prabhu (for example : “Malati prabhu”) . Is that right? If yes, would that mean we can also address ladies as 'prabhu' ? I heard about term 'prabhvi'. Is that OK to use?

Term 'vaisnavi' is also proper to use.

Your servant Namacarya das

HpS - ASA -  Oink!   Oink!   Whoop!     WHoop!    Tom Brown is doing his PhD thesis with some relation to this topic. PhD - Doctor of Phalocracia.    Yes, Prabhu is perfectly appropriate for any devotee, no? Even letter from Prabhupada we saw that it was appropriate title for Bhaktas following the full program.