Raymond the sheep

At what age is it normal for children to be able to read a simple book out loud, clearly and at a natural speed? Today, I bought a children's book, Raymond the sheep, for Nadiyah at the British Library bookstore. She can't read yet, but she has quite an imagination. She has been 'reading' the book to everyone who will listen all day. Anyway, later I hear her big sister (13 years) reading the story in a slow and halting way. Each page only contains 1 sentence along the lines of, "Raymond the sheep lives in Frogsbottom Pond..." However, this pre-teen gets good marks at school. I am wondering if the British education system is different that Canada or ??? I thought it was necessary to be able to read to do any subject in school! Or does this reflect a change in times? Reading is not so important now as people get news etc from TV. Certainly a LOT of TV is watched in this house... Or is it a reflection of home life? Mom can't really read either, but it probably wasn't easy to concentrate on school as the oldest child in a family of countless children (where she probably had to spend most of the time child-minding and worrying about upcoming marriage to a stranger).

I am really thankful for my mom's patience in teaching me to read. So I couldn't tie my shoes or tell the time until (well, let's just say I was really late), she opened up my world to Nancy Drew (ha ha) before school even started.