Seventeen Against the Dealer by Cynthia Voight (Good, 1990, Pbk, 209 pgs, Fawcett Juniper)

Cover has some wear; inside appears to be unmarked. ISBN 0449703754

There's only one thing Dicey Tillerman wants to do--and that's build boats. If she can make a success of doing what she loves, she can take care of the rest of the Tillerman clan, which includes her two younger brothers, her younger sister, and Gram, who took them all in when their mother abandoned them. But dreaming isn't doing, and Dicey begins to find out the hard way that starting a business is difficult, and that you have to expect the unexpected....