A base is bought, edited, edited again, given a tail from another base, fitted with clothes made for its sister, and uploaded. Three years later it is in a public world wearing a hat from a fourth family, and nobody in the instance can tell you where it came from.
We can. AvatarAncestry reads the records the family keeps on itself: store listings, credits, permissions, the species wiki, the line in the readme that says “edit of”. From them we draw the tree, house by house, with every branch sourced. Where the records only hint, we say so, and draw the branch dotted.