It's just been birthday central around here lately. First Elvis , then my mother, then my nephew and Chris's is next Thursday. But I can't let Mom's get lost in the shuffle. She turned 70 on January 14, an event my sister and I decided couldn't go by without some sort of celebration, despite Mom's insistence that she didn't want a party. She got one anyway, an intimate party of four. Susan (my sister) and I drove from Atlanta to Huntsville, Alabama, on the 13th, arriving about 6:30 p.m., while Mom and Dad were at the gym. Daddy, who was in on the plot, had left the front door unlocked. We brought dinner, homemade chicken vegetable soup, angel rolls and birthday cake. Plus, we'd stopped at the Piggly Wiggly in New Hope, Alabama, and bought ice cream for coffee punch and to go with the cake. We set the table with Mom's crystal and china. Leroy, Daddy's shih tzu, let us know when they were almost home. He starts whining whenever Daddy's car reac