I'd hold off until you get your parents' data. I'm a little confused about what's going on, but I think they send a SAR that you can make corrections on to everyone. If there are no corrections, you don't have to do anything. If the corrections aren't available yet (parents' data), I don't think you'd want to make corrections now because you'd just have to do it again. So yeah, just hold on to it again later. BTW, you can make corrections online, so you don't have to use that form.