Seema, Though it depends some on just how much water we're talking about and how quickly it was cleaned up, for the most part, water in the drywall and framing will have all dried in a matter of a few days if the house is currently heated. If the drywall on the ceiling where it got wet feels dry and firm, you'll likely not see any further waterstaining develop, and it won't be a mold/mildew concern.
If there was very much water, one item to check will be any carpeted areas. If a stretched-in carpeting got very wet, it should have been pulled up and the padding below should be lifted to dry, or replaced; the carpeting will dry much better than the pad - that's where moisture will get trapped and could cause problems. So, if there was much water, find out what was done to dry the carpet and pad. If the pad wasn't replaced or lifted, it could be soaking wet for a long time, yet the carpet will be dry.
If the house is currently heated, the walls and ceiling should not be any concern for retaining moisture long enough to cause mold/mildew problems; any padding under carpeting is another story.