What you should do this summer is:
Read to your child. Then read some more. Then more again. Read the same book over and over if your child wants that.
Read poetry and sing songs. Pre-reading children need to be able to get a feel for similarities and differences in sounds, for syllables, for rhythm.
Look at cvc words in the books you read, and show your child how sounds and letters correspond.
Casually ask your child what the illustrations are showing as you go through each book.
Ask your child to pick out words like a, the, at, you in text, plus other words that crop up a lot in any given book (depending on the material, this could be cat, dog, fire, rain, hungry, ate, goodnight, etc).
Do simple jigsaw puzzles.
Let your child practice letters and numbers using sand and a stick, chalk, mud.
When you go shopping, ask your child to read out the letters (L to R) of the shops you visit- BOOTS, TESCO, ALDI, and you can say what the letters spell. You can also have her spell out STOP at stop signs, etc. The point is to make her aware of all the written word in the environment, and repetition will help her actually learn to read those words. Do this as a fun game.
My DCs went to school in the US, where children are really taught to read in First grade (age 6 turning 7). Kindergarten (age 5 turning 6) is the year when they are exposed to phonics. All my DCs were reading before they got to First grade, but other kids were not. They're all university graduates now, regardless of when they started.
Don't be disheartened or discouraged or feel your child is 'behind'. There is no evidence at all that says the British approach of expecting children of 4 turning 5 to read, spell, and write basic words and sentences has any benefit. It just results in many children developing a sense of bewilderment in school, and an idea that they are failing.