DD(13) needs an outfit to wear to DSis's wedding in May.
She's not interested in clothes and just wears jeans, trainers and a hoody all the time. She doesn't have any smart clothes at all and I'm loathe to spend a lot on an outfit that she'll never wear again. But needs must.
I've broached the idea of her wearing a dress but she's saying she doesn't want to. She needs to feel comfortable so I'm not going to push it, but I'm at a loss really. 
Any ideas please?