I think its a long shot but?

Sorry I know its long but please try to answer as much as you can!!!! My 4 yr old daughter has a speech impediment, gross motor and fine motor skills delays. She goes to a special learning center half days 4 times a week. Where she sees a speech therapist, Physical Therapist, and an Occupational therapist. The physical Therapist Has suggested that My daughter get Orthopedic Shoe inserts with small bres because she has Val Gus knees and flat feet. Other then these things She has severer seasonal asthma. I attend College, I’m a single mom I work but money is tight. Our income is less then 800 a month. But the state child support (her dad doesn’t pay but that’s another situation) prosecuting attorney recommended that I try to get My daughter on SS disability. She says if I apply and don’t get it then I can get an attorney that will only charge me if he wins even then he only takes a one time portion of the disability. So I have nothing to loose and she gave me a name of an attorney friend of hers who deals with SS. I called the SS office and they made an appointment with me for an interview plus sent me out paper work in the mail. She told me to bring my daughter’s birth certificate, my license, a copy of her IEP, and a note from her doctor saying that she has read the IEP and she is aware of my daughter’s disability. I went to SS and Applied earlier this week. I heard it is actually harder for a person to win a child disability Claim then an adult. Is this true? How can I help speed up the process and improve her chances of getting SSI? Since I already have a name of an attorney should I go ahead and call him tell him I applied for her and she if there is anything that he can do to better my chances or to alert him that I am aware that I may not win the claim but would like for him to help me fight in court if it comes to that? Is there anyone else out there who has applied for SS disability for their child? What do you think the chances are of getting this benefit for her?