Yes, it is possible for your daughter to have an IQ (Intelligence Quotient) in the average range, and at the same time to have a learning disability. In fact, most children who have learning disabilities do have IQ's which are, in a general sense, somewhere in the average range (which actually covers quite a spread).
Your daughter's grade level scores indicate that she is well behind her normal grade level in the subject areas you described. The gap between expected vs. actual achievement indicates that she should be receiving a considerable amount of special educational assistance, probably in a self-contained classroom for learning disabled children. In such an academic setting she can receive intensive help from specialists in special education and, hopefully, narrow the between her expected vs. actual levels of achievement.
The IQ/LD issue confuses many parents. The IQ test measures a child's general ability to learn, and your daughter's test scores show the consistent finding that her general ability to learn is not impaired. Some children (for example, children with various levels of mental retardation, have limited intellectual ability). In your daughter's case, her difficulty is not caused by limits to her intelligence, but rather by particular limitations in her abilities to process certain kinds of information.
In short, your daughter's situation matches the general profile of many, if not most, learning disabled children, and suggests that she requires a considerable amount of special educational assistance.
Finally, your daughter's medications address two different issues: the dexedrine is a stimulant medication designed to address her ADHD; Paxil is an antidepressant medication which addresses her irritability and anger (which are often, in children and teens, symptoms of a mood disorder).
This information is provided for general medical education purposes only. Please consult your health care providers for diagnostic and treatment options that pertain to your specific medical condition or situation.
*Keyword: ADHD, Learning Disability