I believe the "girl in orange" is Hillary's personal assistant, Huma Abedin. She's quite young, and better pictures [try a Google image search] reveal her to be drop-dead gorgeous. Apparently she is also one of Hillary's most trusted personal confidantes. There have been several stories on the Internet over the past few months, suggesting that the relationship might be very close in another way too, but so far nothing to that effect in any of the "mainstream media" -- fortunately for Hillary!