I know my daughter (she was abandoned after birth and left at an orphanage) would someday love to know the following about her bioparents:
A. All known medical data about either bioparent and their families. What they were known to suffer from, causes of death of any grandparents, aunts, uncles, grandparents, siblings, etc.
B. Some family history. Where did the family live before they lived where last known. Their roots. What drove them to leave their ancestral homes (religious persecution, war, famine) and when and how did they come to the US.
C. Do they have siblings out there somewhere.
D. What does the family excel at? Are there many who love math? Music? Sports? Art? Science? What interests the bioparents? Do HER interests maybe come from her bioroots, for example.
What do the family members look like. Did biodad or mom have thick, dark hair like she does? Are they tall? Short? Dimples? Cleft chins?
Help fill in the blanks that the future parents cannot. Help the child have a connection to their roots and satisfy their curiousity. Curiousity about what might make them who they end up being. Part is nature, part is nurture.
Maybe a scrapbook would be nice?
WE made one for our daughter utilizing all the (appropriate) history we did have and she loves to page through it.