What if a client doesn't know what they want?

Hey everyone! I am really new to freelancing and picked up a client recently for whom I am working on a social media presence. The issue is, that's about as much direction as I've been given. I've come up with and presented a social media editorial calender that she seems to like, but its been a challenge figuring out what type of content she expects me to be generating for her.

I guess my question is, what kinds of questions do you ask new clients to get a gauge of their expectations, particularly those of you that work on social media and content creation? Are there any clarifying questions that you find particularly helpful in establishing a set of goals that you can then structure content around?