How is the rest of her school performance? My DS (aged 8) has just finished year 3 (England, so reception+3 further years), and I started a thread about 4 months back about his reluctance to read.
Several people on that thread said "have you considered dyslexia?" and I, naively, thought because he didn't mix up b and d, didn't report text dancing around the page, etc, that there probably wasn't a problem with this.
However, there was a very noticeable difference between reading and the rest of his performance at school - good at maths, science, great at making up stories with a wide vocabulary (albeit very slow at writing them down). Then my chance attendance at a talk about dyslexia in the workplace made me realise dyslexia is far more complex than my stereotypical "layperson's" picture of it.
To cut a long story short, I had DS tested by an ed psych and he is indeed dyslexic - in particular with issues in working memory, which make it very hard for him to decode phonemes. It doesn't mean he can't read - it just means that at the moment he does so very slowly, and more importantly, the mental effort it takes him is immense (so he comes home from school absolutely knackered and really doesn't want to do his reading homework - it's not that he's lazy or reluctant, he just is shattered).
So I guess I'd say think about the bigger picture - is it just reading, or is it schoolwork across the board? And if there are reasons for suspecting dyslexia, would a diagnosis be helpful to you and your DD? Some parents think "labelling" isn't helpful, and in some cases I can see why they take this position. For us, it is helpful, because DS was starting to say things like "I'm stupid" - now he knows he isn't, his brain just works differently. And it gives us helpful strategies to try to work on the bits he finds hard - computer based games to improve working memory, for instance, helping him to work free from distractions, etc. (And it also gives me useful background for when he reaches secondary - the secondary schools in our area aren't very good, and he's just the sort of child who, without this sort of paper trail, would be written off as "typical boy, bit lazy and can't be bothered..." - with the diagnosis I can push the school to support him properly).