Help me find a dress for 16 year dd

[Countrystroll]

We have been invited to a big family party this weekend to celebrate a birthday with around 200 people. DD is 16 and wants to find a nice dress to wear but is struggling. She wants something longer as she is self conscious of her legs - she thinks they are too heavy. All the dresses we’ve looked at are a bit frumpy or too black tie looking. I want her to feel really good about herself but wondered if anyone could come up with any suggestions please. She usually shops and urban outfitters, subdued, asos.

I feel like the shops are absolutely filled with longish summer dresses. How casual or dressy is this event? Here are a bunch of midi dresses on Next (not all Next brand) but these are quite casual: https://www.next.co.uk/shop/gender-women-category-dresses/length-midi-use-holiday?p=1#673 and here are a bunch that are slightly smarter: https://www.next.co.uk/shop/gender-women-category-dresses/use-occasionwear?p=1#658

@Countrystroll My DDs had favourite shops at that age. I’d look at Zara and River Island and Mango for a start. They have a mix of smart and boho. What style of clothes does she like? Plus, I know this seems harsh, but in a huge group, no one will judge a 16 year old!