Reception teacher here. You are absolutely right that her reading books from school should only contain the sounds they are currently covering in school. Their choice of books for her sound completely bizarre and Ofsted would rip them apart for it.
Speak to them again after half term and explain how much support you are needing to give in order to help her decode the current books. Point out the level of high frequency words in them that she's not yet been taught, and the fact they contain split digraphs ('Magic e'), which is usually Year 1 work. Hopefully, whoever changes their books simply hasn't realised how complex these books are, although it is a massive oversight on their part.
Going forward, as she already has good blending skills with simple CVC words you could choose to work on her sight vocabulary at home, playing games with some of the high-frequency words which have been coming up in her books which she doesn't know yet. The first sets usually contain words like:-
I, the, to, no, go
he, she, me, be, we, are, all, was, you, my, they
said, have, do, so, come, some, when, what,
That's just off the top of my head so apologies if I've missed some. You can Google such lists (known as 'tricky' words). They are words the children can't decode yet for the level of phonics they are working on, but appear in the books at these levels due to the frequency of their usage in the English language. They can only be taught by sight, so the children need lots of exposure to them to help them learn them. This is most fun through games, such as Bingo, splat, treasure hunts etc. Again, you can Google lots of ideas for fun ways to teach tricky words.
Basically, the school should not be sending home books which do not match the level your daughter is working at in school. However, if they persist in doing so, she'll be more able to read them independently if you work on developing her sight vocabulary.
Good luck