Seems I was unreasonable ... no I don’t think so

My last post I asked if I was being unreasonable to withhold news of a step sister to my first adopted grandchild....one taken under false pretences to cover up NHS staff caused injury later blamed on the Parents.
Grand daughter no 2 has arrived and my son has decided that ‘we’ will not disclose this information ourselves, but between my sons ex partner and/ or SS, the adoptive parent will no doubt find out. She won’t be able to have her cake and eat it any longer. We are often told we have no rights to know more than the adoptive parent tells us. That works both ways.
If my adopted lost grand daughter wants to know more she will have to come looking.