Now, for your question about the diagnosis. Diagnostic terminology varies from state to state, so I'm not sure exactly what the school means when they say your daughter is MMI. They are probably suggesting that she is mentally retarded --which means that they believe that she is limited intellectually and may not be expected to do school work at her age level. You need to go back to the people who did the evaluation and ask them to explain their diagnosis and the implications. Ask them specifically if they are saying she has a learning disability or that she is mentally retarded. Also ask them to tell you exactly what her learning strengths and weakness are. I would assume, based on this diagnosis, that they have developed and Individual Educational Plan (IEP), which is also required under federal and state law. If they did not, tell the Department of Education and OFC about this when you call them.
There are lots of ways to help a child with comprehension difficulties, but I would have to know more about the nature of your daughter's learning style and needs. You will find some good general suggestions at the U.S. Dept. of Education website (http://www.ed.gov). Click on the parent section and see the listings under "Helping my Child to Read." To learn more about the special education law, you might try http://www.reedmartin.com or http://ericcec.org/minibibs/eb26.html.