Gap might or Next? When dd1 was 3 and dd2 3 months we went to a wedding and they had matching dresses from Next. I love having them all the same for special occasions Tbh though Monsoon is your best bet - their stuff is lovely.
Having no luck online. All the shops mentioned [gap and monsoon and next] are an hour and half away in nearest city, and I can't risk it as 40 +1 weeks today. Hmmm....really want to go have a root around though!