Well, Abs is 13, and it really depends on the child. Both my kids love Jay-Jays clothes. A gift card from the would be awesome. Even a pamper session. If she likes gaming, maybe a voucher at Reggies for a game.
But if she is a girly girl, Truworths, Foshini, Edgars, Mr Price or Jay Jays voucher would be a good gift. Especially if you want to have the coolest gift!