My DD is also in Reception and also a very keen reader. She reads books in bed and has one lying around most of the time, which she reads silently.
We still continue with the (almost) daily ritual of her reading to us (and us reading to her as well, of course). A few months ago we noticed that she'd try to read a bit too quickly, and her clarity and expression started to suffer. Occasionally while reading she'd go silent, and then pick up at the next paragraph - and when we questioned the bit she hadn't read, she was adamant that she HAD - she'd evidently forgotten she was reading out loud, and started to read silently for a bit!
I assume this is a natural phase of an increasingly confident silent reader, but it made us realise how important it is to continue to develop the skill and enjoyment of reading out loud.
We now really focus on the expression and the meaning of the sentences - she often self-corrects and reads a sentence again if she hasn't got the inflection quite right. We also stop and discuss the meaning of particular words/phrases where appropriate, to develop her vocabulary and comprehension and inference skills.
We also enjoy reading plays where we each take a part, and also poems, where the shape and expression is so important. We also make a game of creating different voices for the different characters, and remembering to use the appropriate voice each time.
Our current pattern is for her to read all of school books out loud to us, plus a selection of harder books to read together with one of us, and a few more straightforward ones to read silently on her own.
I have no idea when children become 'free readers' at DD's school, but she already has a go at reading whatever she fancies. Having said that, there are definitely benefits to be had from using school reading books that are graded according to phonics knowledge and comprehension.