To me, you are describing a dylexic child or one whose tuition in reading at school has been appalling if she, at the age of ten, is still stumbling through letters.
For Heaven's sake STOP trying to get the girl to like reading! It is a traumatic, boring chore to her.
Her parents need to find out whether their daughter is dylexic or not and have her given special tuition if she is.
To an avid reader like myself it is a tragedy that some children and adults today never read for pleasure, but now that your computer can read the news and letters from the authorities aloud to you and practically any book you can think of exists in a good, bad or indifferent film version, or as an audio book, it may well be that reading like good hand-writing is a skill that won't be all that necessary for your granddaughter.
Sad? yes to my mind, but so is pushing a child to do something she dislikes.
I realise that you, and others, are doing it with the very best intentions, but no child, myself included, ever learnt something because we were forced to, or made to feel guilty because we couldn't do it well, or easily.