My mom's birthday is on the 3rd day of a holiday with my aunt and uncle (with their baby). We are going to go to a small cottage by a pebbly beach, and I am wondering how to throw her a surprise birthday without her knowing. My family consists of my mom, dad, brother and me. I have no idea how to get a cake in, get decorations sorted and everything done without her noticing. Any ideas? Simply, "How do I throw this birthday party?"