Angelina's ballerinas: Ms Jolie takes Shiloh and Zahara to a dance class

By Daily Mail Reporter

Mother of six Angelina Jolie treated her two eldest daughters to a girls' day out in Los Angeles yesterday.

The Wanted star, who was this week named Hollywood's top earning actress, took Shiloh, 3, and Zahara, 4, to a dance class in Studio City.

The adorable duo, who wore matching black leggings, took part in a session called 'The Princess Series', and couldn't resist a twirl or two as they made their way home.

Girls' day out: Angelina Jolie took daughters Shiloh and Zahara to a dance class in Los Angeles yesterday

Wearing a strapless maxi-dress, casual flip flops and aviator sunglasses, Angelina walked hand in hand with her daughters after their day of fun.

It was a rare public outing for the family, who have largely kept out of the spotlight in recent months.

In fact, the absence of the famous brood from the spotlight has sparked some concern, particularly for Angelina and Brad Pitt's twins Knox and Vivienne.

The pair, who turn 1 on July 12, have been seen in public just once this year when they were whisked through a Tokyo airport in January.

An American tabloid magazine claims the couple's youngest children both suffer from medical issues.

Fancy footwork: The girls couldn't resist a little twirl as they made their way home

'They're both hypersensitive,' Life&Style magazine quotes an insider as saying. 'Knox has trouble holding down his food. He spits up nearly every meal.'

The source claims Vivienne suffers from allergies: 'Right now, she's on a lactose and gluten-free diet, and she's still underweight.

'Angelina and Brad reportedly feel that the twins are better off behind closed doors for now.

'Because of their delicate state, Knox and Vivienne need to be kept away from anything they could possibly be allergic to. That's a lot easier to do when they're home and in a controlled environment.'

Still, Angelina, 34, recently said she and Brad, 40, hope to expand their family, which also includes Maddox, 7, and Pax, 5.

She said last month: 'We love children, we want a big family, so we never - you know, never say no.'

Where are the twins? Vivienne and Knox have not been seen since January when they were whisked through Toyko airport with the rest of Angelina
and Brad's brood