I assume that you can see that we are headed towards a pretty solid paper about imperialism, although the form that this will take is still unclear. (Will the student decide to write about Kurtz? Kurtz and exploitation? Marlow as the observer of "evil"? Marlow as participant in "evil"? Will the student go back to the original connection between Conrad and Marlow? Or will the student drop the autobiographical connection entirely and write solely about the text? Any, all, and many other options are possible.)
Note where and how this branch of conversation started. Sure, the tutor handled herself very well throughout the preceding conversation, but the critical transition moment happened when Jen dropped her own assumptions about the text and listened more carefully to the tutee.
Now, lest you think that the answer all along was "Imperialism" and that the tutor's job was to swim around until she found that one right answer, let's go back into the original session one last time. This time we'll jump in early on...