please recommend presents I can buy for teenage girls?

[vannah]

Im a mum of two toddlers, so the world of teenagers is a bit alien to me. Worse still, I don't actually know the girls at all. They are 11 and 13, I know they like reading but wanted something a bit more special than book tokens.
Their mother is a friend of my mother-in-law's, and is forever sending my children adorable useful gifts (clothes and classic books)

any ideas?
sorry bit vague...

Go to Claire's Accessories (hair stuff & cheapo jewellry)? Superdrug for some make up sets?

thanks sg, forgot claires...

also H&M and new look good for cheap accessories.

My DD is 14. She was really pleased with hair spray, Impulse body spray, nice bubble bath. DD also was really pleased in getting a £5 gift card from New Look.

I second the Impulse body spray. They have a city collection which my teen loves. For the eleven year old some lip gloss perhaps or a nice tin of pencils or felt tips or gel pens if funds allow. Body Shop stuff goes down well but is pricey.

I have a 14 yr old and a 12 yr old. They love gift cards: iTunes, bookstores, mall stores like Claires or Bath and Body.

brilliant - some great ideas everyone, thankyou!