Maryellen has big plans for her birthday, and she's glad when her old pal Davy shows up to help. If only Wayne the Pain would buzz off - but he's stuck to Davy like glue. Maybe her sister Joan was right when she said that girls can't be friends with boys in fourth grade. Then, on a family vacation, Maryellen finds out that Joan's not so sure about her own plans. One thing's clear: If Maryellen's going to invent a flying machine, become famous, and...