She was a respected lawyer, so she could easily go back to private practice.
She's in a position to take opportunities to run for statewide office in the next few years. Although not much further than that.
Her resume isn't all that impressive (two years as President of the Hawaii state Senate, four years as a congresswoman when Democrats held the majority) so depending on an appointment doesn't seem like a good strategy.
For a full cabinet position, sure; but assuming she heavily backs/chairs Hillary's HI campaign and campaigns among Asian and women groups for her, she might have a shot at some minor deputy under-secretary or ambassador posting.