Hedieh "Roshan" Ghaffarian will be on hand for next week's state dinner for China. She will join the White House full-time next month after she moves to Washington.
The White House says Ghaffarian immigrated to Los Altos, California, with her family as a child after the Iranian revolution.
In her twenties, she started a flower business in her parents' garage.
First lady Michelle Obama announced the appointment Thursday. Mrs. Obama says Ghaffarian's life story is a reminder that the American Dream endures.