Nordegren and her son watched the first semifinal match Friday at the Sony Ericsson Open, where Andy Roddick beat Rafael Nadal 4-6, 6-3, 6-3.
Woods' wife and son arrived shortly after the start and sat under an awning in club seats near the players' lounge. Charlie stood on his mom's lap.
Woods has attended the tournament in the past to root for his friend, Roger Federer. The top-ranked Federer lost this week in the fourth round.