She’s the lady in red! Page Six has learned that socialite Bettina Anderson was sitting directly behind Donald Trump Jr. and his fiancée Kimberly Guilfoyle at the recent Republican National Convention. The Daily Mail reported last week that Don Jr.

was seen looking cozy with Anderson — and even “locking lips” — over brunch recently at Honor Bar in Palm Beach, and that it’s the “talk of the town.” The tabloid published further pics of Anderson and Don Jr. attending the same party in Jupiter, Fla.

, last month, which was allegedly not attended by Guilfoyle. Anderson, 37, can also be seen in photos, Page Six has learned, sitting behind Trump and Guilfoyle at the convention in Milwaukee, Wis., in mid-July.

The fashionable socialite attended the Wednesday night of the GOP event, and can be seen in pics applauding in a glamorous red outfit. She was also photographed chatting with Don Jr.’s ex, Vanessa Trump, 46, at the event, and we hear the two are close friends.

Sources said she attended with Vanessa. In some shots, the duo were seated next to each other, and are also nearby the rest of the Trump family. Anderson also can be seen in background of an image posted by Don Jr.

on Instagram of himself and Hulk Hogan at the convention. A GOP insider told us that the seat where Anderson was spotted was “open” and “not an assigned seat.” Back in Palm Beach, depending on who you talk to, Don Jr.

and his fiancée of four years Kimberly Guilfoyle are on the rocks.