My dd is nearly 2 and a half. Me and her dad look after her 3 days a week and she has a nanny share for the other 2 - which works well. Is it a good idea for her to start pre-school for part-days before she turns 3? I know we won't get any funding until then but wonder if it would be better for her developmentally to start sooner in a more structured environment. And if so, how much time a week is useful? Instead of the nanny or in addition to?