I'm trying to help my Mum find a nice dress for my sisters wedding. She found a lovely one after searching for ages but it's sold out and isn't being restocked 
She's 55, a size 24, and wants a maxi dress with some sort of sleeve. Preferably to the elbow or just slightly above. Needs to tie in with the colour scheme somehow, which is blue and silver (I think any kind of blue will do as the original dress she found was navy and white).
Can anyone help? I've tried ASOS, Littlewoods and Dorothy Perkins but nothing is suitable. She usually shops at Marisota and other similar places so I thought you lot might know some shops we've not thought of 