Trouble With Venture Partner?

A friend and I are thinking about doing a business together. It makes sense--our interests and skills come together in a complementary way. We have talked about it and gone to two seminars about it. Her part in it is clear; mine is more murky. I am having trouble visualizing how my part will come together Recently I have felt her digging me about some wierd things. I am also worried about some of her outlooks. Is it really a good idea that we go into business together? I am not sure. But I need to figure it out very soon.