I think any advantage Sarah might have gained by being a policy wonk over the past couple of years has always been greatly overrated. Maybe those who say that forget how long presidential primaries and campaigns now are.
She, or any other candidate, will have more than adequate time to prove or disprove their knowledge of the issues during the primary campaigns and debates which will run for about nine months, from this summer until next March or so. Then we'll have almost as many more months for the primary winners to further dazzle us with their knowledge.
Not sure what Sarah will do, but all this nonsense about her great need to show her stuff on policy the past two years is mostly something for those commentators who never stop thinking about politics to navel gaze about. All the eventual candidates have more than enough time and opportunities remaining to show us what they know, or don't know.