A Southeast Washington mother is protesting a private school's decision to bar two of her children from returning to the school next year under the District's school voucher program, which uses federal taxpayer money to pay the tuition of low-income children.

Betty Murray, 28, a D.C. school bus driver, said officials at Rock Creek International School in Northwest had told her that they were not equipped to handle her children's behavioral and academic problems. She said that the head of the school, Daniel Hollinger, agreed to speak with her Wednesday but left his office through a window as she waited in front of his closed office door.

Hollinger said yesterday that he did not use the window and was not trying to avoid Murray. He met Murray yesterday, and said, "We are working with her to see if it is possible for her children to continue at RCIS and be happy and successful here."

The situation at Rock Creek comes at the end of what the Washington Scholarship Fund, the nonprofit group that manages the $12.5 million voucher program, has called a successful first year. The vouchers are being used by 983 students at 53 private or religious schools, and officials said they expect to award an additional 1,080 scholarships for the coming school year.

Sally J. Sachar, the fund's president and chief executive, said that eight voucher recipients have been expelled from their schools since the fall and seven others have been told that they cannot return to their schools next year. There are few complaints from parents, she said, with Murray being "the most unhappy parent we have had."

Murray said that during the year, she spoke often to Sachar and other staff members of the fund about what she felt were inappropriate punishments for her son Cornell, 9, and her daughter Chrystal, 5, and lack of effort to help them improve. Sachar said she replied: "Betty, you have to decide if this match is working for you and your family, and if it is not working . . . one of the beautiful things about this program is we can work with you to find another placement."

Asked about this yesterday, Murray said, "I will not run." She said she is looking for a lawyer to fight the school's decision. Her son Cortez, 7, who also attends Rock Creek, is also affected, she said, because although he is allowed to return, school officials told her that it might be uncomfortable for him to do so without his siblings.

When the voucher program began, some educators expressed concern that low-income students would have difficulty adjusting to schools full of affluent children.

Tuition at Rock Creek, which has 29 voucher students, is about $18,000 a year. The voucher program pays $7,500 for each of the Murray children, for a total of $22,500 this year. The rest is covered by school scholarships.

Rock Creek, whose main building is at 1550 Foxhall Rd., offers internationally oriented programs from pre-kindergarten through eighth grade. Even though the school has many more voucher students than most non-religious schools, it has been generous with its funds, Sachar said. The school arranged for voucher students' expenses during a recent school trip to Jordan to be paid for.

Murray said she was annoyed that Cornell was suspended for a day earlier in the year for replying "You're a fat white girl" to a child who had allegedly called him a "nappy-haired black boy." She also complained that Chrystal was accused of misbehavior on a bus, which takes children to an after-school day-care program, on the basis of reports from other parents, without any written statement by the driver.

But she said she was particularly irked when Carole Al-Kahouaji, director of the Rock Creek primary and middle schools, told her Wednesday that Cornell could not return in part because he needed individual tutoring and the school did not have enough staff for it. She said that Al-Kahouaji cried when she said that the two children would have to leave and added that it was not her decision.

Murray said she reminded Rock Creek staff of earlier promises to help Cornell. "You have just told me you set up my baby to fail," she said she told them.

Murray said that as she waited Wednesday for her meeting with Hollinger, school business director Scott Fedder told her that the head of school could not see her after all. When she refused to leave, she said, he called police. She said she opened Hollinger's door and saw that he was gone, the open window his only possible exit.

"You mean to tell me he was not man enough to talk to me?" she recalled asking Fedder. "He sent someone else to do his dirty work?" Hollinger said that he "left the building discreetly" when Murray was not looking and that he is eager for his school to provide a place for students from "any economic situation."

Betty Murray talks with Daniel Hollinger of Rock Creek International School. She said the school has told her it doesn't have enough staff to provide tutoring for one of her sons.