There is no mention of the priesthood period, except for the single reference to the royal priesthood which refers to Jesus and Jesus only.  The earliest Christians were Jews who were very familiar with priesthood, it was still active in their lifetime.  Jesus, Founder, was Himself not an ordained priest and chose not to be born of the priestly tribe.  He refers to Himself as a teacher (rabbi), and His followers initially considered Him a prophet.  The concept of ordained priesthood is a gradual understanding (perhaps initiated by the Holy Spirit - see how that works?).  Perhaps She is still working, further unfolding our understanding of servant-leader priesthood.  Perhaps that includes the understanding that gender (in this instance) is an accident of nature, and totally unrelated to the call to ordination.