What is 'average' attainment for a 7.5 yo school-girl?

[CSLewis]

I've been home-educating my children since birth, and my eldest daughter is now 7.5. However, with the advent of my fifth child in December 2010, I am looking into the possibility of sending her, and her younger sister (5.5) to school.

I'm interested to hear what your 'average' (not the top 25% of the class) 7.5 yo is able to do in terms of reading, writing and maths. Not what they are being taught (I can access a NC framework site for that), but what your child actually knows and can do, IYSWIM.

An added complication is that my eldest dd has an August birthday, so would already be the youngest of her class - currently Y3, going into Y4 in September. I am therefore more concerned than I otherwise would be that she is not too far away from where the average members of her class already are. I'd really appreciate getting an idea of the range of abililties and attainment in her age/year group. Many thanks.

dd is 7.3 so she reads chapter books, is free reading at school and at home is reading My Naughty Little Sister, Pippi Longstocking etc.
In Maths she is confident at adding and subtracting 2 figure numbers,she understands multiplication and knows her 2x,5x,10x,3x and 6x and learning 4x. She is happy using money and can tell the time both analogue and 24 hr clock.She is able to name and describe all 2d and 3d shapes.
She writes confidently using spellings she has learned alongside her own phonics interpretations. She uses capital letters, full stops, commas and speech marks pretty reliably.
Dd is amongst the top groups of year two if that's any help.

At end of Year 3 my DS knows all his times tables, and is confident with his division facts too.
Greater emphasis on worded problems in maths which he enjoys.
He is reading well, chapter books like Beast Quest, Jack Stalwart, Dick King-Smith, Jeremy Strong.

She is a year younger than dd. Most of her class were free reading chapter books of authors similar to btp's list. Writing would be a short story, poem or description using adjectives, strong verbs (ie not just said or went), punctuation including commas, speech & question marks, and comprehension questions based on a given text. In maths the main objective was to learn all times tables and then division, randomly tested to time. Also concepts such as time and money with associated word problems and basic geometry(ie.angles of a triangle).