Charts are often given as gifts, blank, so the recipient can fill them out. It's okay to have unknown blank spots because of lost records; write down what is known now, before it is forgotten. To fill mine out, I gave a blank family tree chart to my mother and another one to my mother-in-law and asked them to fill in as much as they knew. I took both charts and filled in the other half from the information on each others chart. This left me with two complete charts-one for each of my children.