MY GRANDDOUGHTER IS A SMART 12 YR. OLD, A/B STUDENT

MY GRANDDOUGHTER IS A SMART 12 YR. OLD, A/B STUDENT IN SCHOOL AND SEEMS TO BE KIND OF AHEAD OF THE OTHER 12 YR OLDS, HOWEVER SHE WILL DO THIS PASSING THING, OR SHE MAY BE SITING READING A BOOK ON THE COMPUTER AND SHE WILL START LEANING A BIT FORWARD AND WILL START TO SHAKE HER ARMS AND HANDS. SHE HAS DONE THIS FROM THE TIME SHE WAS A BABY AND IT SEEMS TO BE GETTING WORSE.