Seems to me, judging by the growing number of posts about Reception children not liking/being able to read/write/do maths, that there is increasing pressure on schools to push younger children to reach higher levels. It just doesn't work for all - or even the majority. I'm not saying hold back those who want to read/write or not to teach them adequately, but I loathe the pressure on parents and children, the kind that makes them feel inadequate 

Children at that age develop in different ways, at different times, and that is perfectly normal. Trying to squish them into same-pace learning is so utterly Gove-like daft!
Off my soap box, OP, I would add that one of dd1's best friends didn't read much till she was 7, was on green level in Y2, but is now in Y4 and zipping ahead. There were heaps in both my dds' years who weren't keen on reading aged 4 (especially boys, iirc) and little but often - ie 5 minutes per day, most days - got them there in plenty of time for when it starts to really matter.
Finally, my brother (now aged 49) didn't really enjoy reading until he was at Uni. He is a very successful designer, has written a book, and is fluent in three languages - so perfectly literate, just didn't like reading much as a child 
Easy to say, but I would try and relax.