Why does my Grandaughter write all her words backwards?

The condition is typically known as dyslexia.

Here's a cut-out from Wikipedia:

"Reversals of letters (b for d) and a reversal of words (saw for was) are typical among children who have dyslexia. Reversals are also common for children age 6 and younger who don't have dyslexia. But with dyslexia, the reversals persist"

I can't remember the exact term but it is a legitimate disorder. Have her get an appointment with an opthemologist (more specialized than an optometrist) and ask her school to evaluate her for a learning disorder. This complete reversal is not normal and can be caused by either a problem within the eye or in the part of the brain responsible for language.

I have a five year old daughter and she too write some of her letters backwards, I was concerned about it so I asked her doctor and her teacher about it, they both said that it was normal for her at her age and not to worry about it she will grow out of it.I still think its strange, so I help her as much as I can to practice writing all her letters and the ones that she writes backwards I make her write it until she gets it right and then we move on to another letter, but not unitl she gets it right.