Also, kids who are distracted by fears or worries often have real trouble getting meaning from reading. Is your daughter generally happy, or often full of worries, or, is she preoccupied by some thought or life event, such as a break-up with a boyfriend, or an illness in the family? If so, she might be experiencing anxiety or depression, both of which are treatable conditions. It could also be that she has a condition called Attention Deficit Hyperactivity Disorder (ADHD) which affects the way a person can focus and gain meaning from reading or lectures. (Does she have a history of not being able to attend in at least two different types of activities?) She could also have a learning disability that affects her ability to read for understanding or her memory. (Has she always had trouble understanding what she reads, even though she's a bright little girl?)
It's important to know that maybe none of these fairly serious things are causing her difficulty; she may simply have never been taught how to read in a way that helps her retain information. There are specific study skills, such as one called SQ4R (ask her teachers or the LD specialist in the school if they know about this technique or others) that help kids read with much better comprehension. Has your daughter really ever been taught how to read in such a structured and purposeful way?
It's important to ask the school if they have answers to all the questions that have been raised above. If not, you should request that your daughter be evaluated to get at the root of her difficulty remembering what she has read. Remember if you suspect that she might have some kind of special need, and you ask the school to carry out an evaluation, they MUST do this under law. Don't take no for an answer.