How do I know if my child has a learning disability?

My God-child is five but her speech skills are slow and her behavior is more like a 2 or 3 year old.  For her 2nd year she spoke only a few words the entire year and did not learn to say her own name until she was nearly 3.  Even now she speaks with an impediment making much of what she says difficult to understand.  A neighbors 2 year old speaks in a clearer manner.  

My God-child associates many items with words she hears in movies (like character names) and though corrected frequently, she still associates the thing/person with the wrong title.  She has trouble counting as well.  She counts 10, 11, 12, 13, 18 for example.  We've tried working with her with blocks and flash cards and corrected her with her homework but after weeks of work she still counts the same way.

I am very worried.  Her parents are military and have tried several times talking to the military doctors about the child but the doctors continually insist she will catch up but she is not.  I have tired to search web sites to find information on developmental disorders in children but can find no sites with comprehensive lists of symptoms for a variety of problems.  Sites on specific problems have such information but I don't really know what the problem is so I don't know what web site to go to.  Her parents are having her evaluated through the school but are very frustrated as it is taking a long time (3 months now) and they have not been told anything.  Again, it is a military school (for enlisted personal) and everything runs slowly.  I am at a loss because I love this child and her parents and want to help but don't know what to do.  I can not even make suggestions about where they might find answers as I don't know where to begin to look myself.  

Please help.