In Scandinavian countries kids don't start formal education until around age seven compared to the UK's four+. All pre-school learning is focussed on play, investigation, nature and developing a love of learning for its own sake. By age 11 most Scandinavian kids are outperforming their UK counterparts in academic studies, despite starting two years later, esp boys who in the UK we stick in school and at a desk WAY to early, when they really would have been much happier still charging around running their energy off, and invetsigating the world around them.
Statistically in education terms autumn born girls achieve best, and summer born boys achieve least well (yes, I know there are exceptions to the rule, genetics and environment plays a part too; we're talking in general statistical terms)
8/9 years ago I had to fight tooth and nail right up to David Blunket to get my 26/8 born DS3 DECELERATED a year because I didn't want him in school at barely 4. I managed it and he is just finishing primary this month. He will be lucky tyo achieve 4b's in his SAT's; he is an immature child, and only averagely bright, had he gone into the year he should have chronologically, I think the education system would have set him up to fail before he'd even got started; he wouldn't have managed to hold his own and wouldn't have fitted socially with his peers by junior stage.
Your autumn born DD will probably find school a breeze and love it. DONT rush her please, play is pre-schoolers work, learning to love learning for its own sake is a life long skill worth having.