Setting
I am currently an undergraduate student in chemistry and I have recently started working on an undergraduate research project in a known laboratory in the US. I am very passionate about the topic, however I have problems with my supervisor, who is a PhD student.
Problem description
When I came to the lab asking for a topic to work on, the Professor assigned me to one of their students, which appears to be common practice, so I did not question this. However, I found out later that my supervisor (the student) was the only person in the lab working on the topic, and that she herself had only started working on it not long ago. After several days in the lab, my supervisor has not revealed what the eventual goal of my project will be, and from the way she behaves (stressed out, impatient towards me asking questions, which is an additional problem), I suspect that she might not know herself (quote: "we'll figure out along the way"). This is severely frustrating. I am aware that research is an open-ended endeavour that might be changed as new situations arise, but I thought that undergraduate research should be something self-contained, with a clear goal and time-frame, and usually well-thought out by an experienced researcher? I am aware that one possibility to resolve these issues could be to simply talk to my supervisor. However, there appear to be some barriers, which leads me to my question.
Question
How can I approach the situation without ruining my standing in the laboratory and appearing like a complicated student, even though I am not? I would love to continue on this or a similar topic in this lab, but the current situation is very unpleasant for me.
I feel like I cannot talk to my supervisor directly as she seems impatient and stressed out, and at the same time inexperienced with supervising undergraduate students. I fear that this could make the experience even worse, with my supervisor getting angry at my criticism.
The other option I can conceive of would be to talk to my supervisor's supervisor, and ask for some kind of intervention from above. But this could also backfire in many ways, possibly making me look complicated and unwanted in the lab altogether.