My sister's BI/B2 visa was cancelled under the 'Application Withdrawn' category, because she was pregnant (7 months). (However, her toddler's passport was cleared for entry.) She was said to have misrepresented herself at the Visa Interview (6 months earlier) by not saying she was pregnant while applying.

How does she appeal/clear the allegation of 'misrepresentation' from her home country? How soon can she reapply (obviously after delivery)?