Autism traits and speech

Hi, 

    My child is waiting on an assessment and I keep asking the health professionals on how many traits a child must show to be diagnosed with autism? Unfortunately, they tell me they don't know. I was wondering if any one could help me out on advice with this please. My child has two, doesn't talk a lot and will not touch or eat solid foods. 

Also my child says words in context, but not enough. Will my child ever speak or is this the only forms of communication?