At the part where Tom Hanks and Meg Ryan have become friends she asks him over the Internet if he is married. Shortly before that she told him that her internet friend had just broken up with his girlfriend when they got out of an elevator. Why would she then ask if he was married??
The reason she asked him if he was married is because Joe Fox (now her advisor on her online relationship... which he now knows is with himself) has put the idea in her head that she has possibly been lied to.