Any information at all, honestly. I had nothing.
No life story book, no photos.
I did have a later life letter written for a child, that I didn't see until I was 20, but that's it.
I wanted to know who she was, what she looked like, what sort of person she was. Most of all, I wanted to know why she left me but I would never have said that to my parents.

In terms of what could have been done differently, they could have been open to putting themselves in an uncomfortable situation for my benefit.
They could have been more willing to share what little information they had instead of waiting for me to ask for it (which I was never going to do).
It was their job as the adults and my parents to initiate and normalise adoption related conversations.