Eight-year-old Juliana-Rose Hatcher had tracked Santa Claus all of Friday with the aid of NORAD's Santa hotline, before she got some unexpected help from Michelle Obama.

The first lady stayed behind when her husband, President Barack Obama, and daughters Sasha and Malia hit the beach on their Christmas vacation in Hawaii to answer calls from children trying to pinpoint Santa's whereabouts.

She asked me what I wanted from Santa and I told her an MP3 player and she said her daughter wants an MP3 player too, Juliana, of Goose Creek, South Carolina, told Reuters.

Her mother Jennifer said at first they thought it was a joke or a prerecorded message but quickly realized wow, it really, really is her.

The White House said the first lady spent about 40 minutes talking with children who called the line.

NORAD, a U.S. and Canadian military organization for aerospace and maritime defense, says it uses radar, satellites, high-speed digital cameras and fighter jets to track Santa.

A global map showing his progress, along with links to satellite video of Santa's sleigh flying by and holiday games in seven languages, is at http://www.noradsanta.org/

Austin Futch, 10, from Memphis, Tennessee, said he quizzed the first lady about a few things on his mind concerning life in the White House.

He wanted to know how it felt to be surrounded at all times by Secret Service agents -- not too bad because they are nice guys -- and if it was hard being married to the president.

No, he's a pretty good guy, Michelle Obama told him, according to a transcript of the calls released by the White House.

I mean, it's a tough job and sometimes you want to do everything you can to help him, but it's pretty easy being married to him. He's kind of funny -- fun to hang out with.

(Reporting by Alister Bull; Editing by John O'Callaghan)