DD remembers letters and sounds when illustrated with pictures, but her mind goes blank when she is tested on a bare letter

[tricot39]

Any suggestions for how to help her? I feel bad as she spent most of last year rattling off the phonic sounds using a poster of her room so I didn't pay much attention. Now realising that she doesn't have a firm grip on her letters and sounds at all so her reading is mainly about guesswork! I have tried working with her on plain letters but what I am trying doesn't seem too effective :( All suggestions gratefully received! Thanks

For some children the pictures (actions, songs and games) are helpful for others they are a distraction.

I would work with a limited number of sounds and build up.
Write the letters on postit notes or squares if scrap paper. Personally I would start with 3 sounds that can be combined to make a word - a-m- t
As your daughter what is the first sound she can hear when she says the word mat. If she correctly says /m/ ask her if she knows which of the letters is the spelling for the sound /m/ (if she can't simply tell her) repeat with the rest of the word until she's built the whole word. Using the paper letters as a model ask her to write the word mat and say each sound as she writes the letter. When she can confidently recognise the letters take away the paper letters and introduce a new sound (man or sat or pat). I would always start from the word she knows to start with just to reinforce the letter/sounds.
You might find you can work fairly quickly (a new word each day) but don't worry if you have to stick with the same word for a week or more.

I would also get her an eye test. Pictures are much easier to see than individual letters.

Make sure the optician tests her vision at reading distance and doesn't just use the std poster on the wall far away.

Thanks for those suggestions! From basic DIY experiments it does seem an eye test will be useful :(