My niece is nearly 12 and suddenly she's got a bobble head.

BTW - Bobble Head - where eye rolling is accompanied by a head roll and the head stays on a tilt and the hands *almost* go on the hips

My neighbour complained of the exact same thing two days ago - her daughter suddenly got a Bobble Head.

It seems to be an affliction suffered by tweens, immidiate pre-teens and is replaced by a shoulder shrug and sneer when they are about 15ish