It is definitely probable she will be the Democrat candidate, however:
Superdelegates are "unpledged" in the sense that they themselves decide which candidate to support. (In other words, they are not allocated according to voter preferences as the majority of delegates are.) Pledged delegates can change their vote if no candidate is elected on the first ballot and can even vote for a different candidate on the first ballot if they are "released" by the candidate they are pledged to.
A super-delegate can’t change candidates without Mr. Bill’s permission.