Is it appropriate to suggest to a professor how to communicate more clearly?
For now, I would suggest with responding to statements such as "We will do X" or "It is important to do X" with something along the lines of "Agreed. Shall I start working on that now?" Perhaps she'll take the hint and start communicating more clearly, in which case the problem is solved. In any case, over time, you'll probably get better at understanding which of these statements are general statements about the future and which are implicit requests for action.

If asking for more clarity doesn't work, have a chat with her and explain that you find it hard to tell when she's asking you to do something and when she isn't and asking her to be a bit clearer. I'm sure she won't be offended and, if she is, that's a huge sign that you need to find another advisor!