Okay, no jokes about getting Britney Spears between the covers. But the “Oops!. . . I Did It Again” pop queen, 19, is said to be shopping a work of fiction among New York publishers. The proposal is for a Mother’s Day parable that the former Mouseketeer, who once said that her favorite authors are Danielle Steel and Jackie Collins, plans to co-write with her mother, Lynne Spears. The Web site Inside.com quotes literary agent David Vigliano, who says he is representing the Spearses, as stating that the authors hope to have the small gift book published in time for Mother’s Day 2001. Next week, the elder Spears is expected to meet personally with publishers, while her daughter reportedly continues a concert tour of Europe. Should the project sell, this will not be Spears’s first foray into publishing. Last spring, Th ree Rivers Press published the paperback original “Britney Spears’s Heart to Heart,” co-written by Lynne. A rep from Crown Books told Inside.com that sales hit more than 150,000 copies. That’s pretty good. Other musicians-turned-authors include Jewel, Eminem, LeAnn Rimes and TLC’s Tionne “T-Boz” Watkins.