From what I could find, she isn’t eligible to run until she is 35. https://www.usa.gov/requirements-for-presidential-candidates#:~:text=The%20U.S.%20Constitution%20states%20that,United%20States%20for%2014%20years
That says anyone who meets the requirements can declare their candidacy.
It isn’t always that they don’t know what they want, sometimes they just don’t know how to describe what they want, or they may know what they don’t want.