Received Non-Identifying Info

Received Non-Identifying Info :) It was bittersweet to read some of the info. however, I did find out nationality, reason for my adoption, That my mother was 40 when I was given up, some details about how many siblings i had at the time and that my birth mother was from a large family. I was told by the agency, for a fee, they will have an investigator do a search for me. Which is great! However, Due to the fact that she was 40 when I was given up it would make her in her late 80's now :( and if she has passed...they will not give me any info for family privacy reasons...and I am out $400 :/ Not sure if I can risk that much. Thinking of still searching on my own I still do not have any clue where to start searching. I search the internet and these type of sites and nothing ever comes up....any ideas would be appreciated.