A perfect word for the phenomenon of which you are speaking, at least in matters of religion, is discipling. The goal of Christian discipleship, for example, is for the more-mature disciple to "reproduce" him- or herself in the life of the person who is being discipled. That person in turn disciples another Christian who is less mature than he or she, and so on.
I don't think, however, you'll get away with "She has been tremendously helpful in discipling new employees." Perhaps the word mentoring would be useful, in that it denotes the efforts of a more-experienced employee in bringing a less-experienced employee up to speed through teaching, exemplifying, encouraging, instructing step-by-step, and more.
A more prosaic word, of course, is teaching (or instructing). Mentoring, however, has a nice ring to it.