That is correct.  I can tell you that with a roll of 20 she would definitely see something.  Divination, being a rather nonstandard subject, does not have the strict success milestones that other abilities often do.  In general, though, it depends on how specific an event/subject you are trying to foresee.  For example, a question of "What will happen in (person)'s future?" will be more likely to grant some vision than "What will happen to me tomorrow at lunch?"