Personally it's risky ever buying anyone clothing without them specifically asking for it. I'd much rather a voucher where I can choose something for myself, rather than something that I will have to pretend to like then have sit in the wardrobe forever or until I do a charity shop clear out. It doesn't show lack of thought if it's for a shop she really likes or a favorite restaurant.
She's not a 'yoof'. She's a woman in her 30's.