When the family arrives at the hotel after walking through the woods, Raven is wearing a different hat then she started the walk wearing, and her hair is disheveled. Then, when she is shown walking into the lobby, she is wearing her original hat and her hair is perfect.
In the scene where Chief James Porter is watching his daughter dancing through the window, the curtains are all the way closed. When he gets a ladder to climb up, the curtains are a 1/4 of the way open.
In the early scene of the Chief and Nancy in bed they show Nancy putting a pink sleep mask over her eyes. When the chief wakes her she is seen raising the sleep mask to her the top of her head but when shown from over his shoulder, the mask is nowhere to be seen. When they cut back to her again, the mask is back on top of her head.
Georgetown University is 2.8 miles from the White House and is well within the restricted airspace zone. It would have been very unlikely that a plane would be allowed that close without being shot down, let alone skydivers being able to jump from it.
Near the end of the movie, Wendy Greenhut tells Melanie that Melanie was her inspiration to apply to Georgetown University. However, it would have been impossible for Wendy to apply to Georgetown for the same class year as Melanie, since Melanie's character was already on the waiting-list. The application process was too far along for this to occur.