Dd3 had a yellow raincoat last year from m and s that she simply loves. It's ok for now but she's really shot up over the last couple of months and I think it's days are numbered. I mentioned getting another raincoat and she said 'as long as it's yellow...'
Rashly I agreed and now I can't find one. Boden have one in the boys range (ridiculous, it's just a yellow coat) and it would be fine but they don't have 11-12. Lots of other ones I've seen aren't in a big enough size. M and s this year have a whole lot of pastel and white ones 
There's one that comes up on not on the high street but it's a bit naff with big buttons and rather expensive too. Budget around £40 but could go higher if fabulous. I guess we are looking for a sort of fisherman vibe.