A federal judge yesterday scheduled trial to begin on Feb. 1, 1983, for former Youth Pride Inc. director Mary Treadwell and three other former officials of a Youth Pride real estate spinoff who were indicted six months ago on fraud charges.

Government prosecutors and lawyers for the defendants agreed to the date at a hearing before U.S. District Court Judge John Garrett Penn. Prosecutors said yesterday that the trial could take as long as two to three months, involving as many as 100 prosecution witnesses and hundreds of documents.

In an indictment returned last February, a federal grand jury charged that Treadwell; Robert E. Lee; Treadwell's sister, Joan M. Booth; and Charles W. Rinker Jr. stole and misappropriated thousands of dollars from federally funded housing projects that they managed through P.I. Properties Inc., the real estate spinoff.

The grand jury alleged that Treadwell and the others, while portraying P.I. Properties to the government as a nonprofit business, used it to illegally obtain money to fund their own profit-making business enterprises or to pay personal expenses.

All four defendants have denied any wrongdoing. Treadwell's estranged husband, accountant Ronald S. Williams, also was named in the indictment but pleaded guilty last April to a lesser charge and agreed to testify for the government. Johnny Mickens III, formerly Youth Pride's chief financial officer, pleaded guilty to tax violations in a separate case and also agreed to cooperate as a prosecution witness.

Rinker, claiming violations of federal speedy trial law, has asked Penn either to dismiss the charges against him or grant him a separate trial, possibly as early as Oct. 15. Penn has not yet ruled on Rinker's request.