Help Me To Understand

I would like to hear from anyone who can help me understand why some birth parents can't be alittle helpful when asked. I've known almost my whole life I was adopted. I've done whatI've done what I could to search, The last few years even harder. I was able to pay for a search through the agency that handled my adoption last year, they located my birth mother in Nov. of last year and she waited until yesterday to finally respond. She told them not to release her information and not to contact her again. NO information sent at all. I had said I would respect her wishes if she wanted no contact I just wanted some questions answered if nothing else, I have a child that has had medical problems and I am repeatedly asked if things run in my family,it would be greatly appreciated and helpful and stress relieving if she would answer medical questions to help my son not go through so much since we have to guess.And she gave nothing, not one word to help my son and me. I just don't understand what it would of hurt to pass along this information, I couldn't find her from it. her privacy would be intact. What harm would it of done her to help us in that matter, how can some one deny such needed information. I'm like anyone else who is adopted I would of liked to know everything, but I could of been happy for now anyways with the medical history being that is very important at this time, I've spend 5 years of guessing, is it so much to ask for a relief in this area? Am I wrong to believe I deserve that much. Why are we treated as children our whole life, no right to know anything, always left in the dark, when will someone turn a light on for us. What is the harm of knowing things especially the older we get, our family seems to be dealing with so much sickness and death and I have no ideal what to be on the look out, I have 3 boys who have to take half a guess at this that they may have to worry about. One sided history is not fair. If any one can help me understand what a little information would hurt I'd appreciate. To wait and hope and end up with nothing is a hurtful blow.