I have always had a tendency to be free from any conditioning and any limiting mind-structure. So I do not care much for traditional rules, not even the yoga ones, for they are limiting and contradicting the essence of freedom in some levels.
If you have been taught that you need initiation in order for any form of yoga to work, [I]your experience will match your belief[/I]. Your friend’s belief is that she doesn’t need initiation and that her way of doing kriya yoga is very powerful, hence: that will be her experience.
So there is no yes or no answer for this question. I cannot say yes you need initiation or no you don’t need initiation in order for Kriya Yoga to work. If you belief you need initiation, then yes you will need initiation. If you belief you don’t need initiation, than the answer will be no, you don’t need it in order for Kriya Yoga to work perfectly for you. There is no rule, no solid answer for anything. It all depends on your mind mate.