worried about genetic defects

My mother in law has deformed feet. I have never seen her feet because shes always wearing socks. Her deformed feet prevent her from walking long distances and shes always asking for a wheelchair rental when we go to amusement parks. According to my husband, his grandmother had the same feet as my mil. She also had type 1 diabetes and so does my mil. What are the chances of this happening if we have a daughter? We also have a three year old son and he was born with no defects.