FOR LIZ GRANT'S granddaughter, a third-grader on the honor roll at North Philadelphia's Joseph C. Ferguson Elementary School, an "opportunity scholarship" to attend private or parochial school would mean a more challenging curriculum.

"She's very smart," said Grant, 63. "She needs a school that's gonna keep up."

Yesterday, a bill that could allow Grant's granddaughter to attend a school like that passed in the state Senate, 27-22.

The bill would establish vouchers for students who attend and live within the attendance boundaries of the state's 143 lowest-performing schools. Ferguson is one of 88 Philadelphia schools - 25 high schools and 63 elementary and middle schools - on that list.

The measure faces an uncertain future in the state House.

"I can see this school emptying out" if the bill fully passes, Grant said yesterday. "A lot of young parents complain."

For a family of four in the Philadelphia School District with an income of $29,055 or less, the voucher would be worth $6,779 (the full amount of the state's per-pupil subsidy to the district). Families of four with incomes from $29,055 to $41,348 who qualify would get $5,084.

Tuition at elementary schools in the Archdiocese of Philadelphia varies, but tuition at high schools was $5,350 last year (plus a supplemental fee of $1,100 for non-Catholic students).

Many high-priced private schools would remain out of reach for city students, though, and, unlike public schools, private and parochial schools aren't forced to accept students, even those with vouchers.

Opponents argue that the vouchers - a key piece of Gov. Corbett's education platform - will take more money from school districts already suffering from big cuts in state aid.

State Sen. Anthony Williams co-sponsored the bill and argued during yesterday's Senate debate that vouchers would give some students a way out of public schools that "failed students for generations." He voted for the measure - which also includes changes to the state's charter-school law - along with state Sen. LeAnna Washington.

Philadelphia state senators voting against it were Vincent Hughes, Mike Stack, Christine Tartaglione, Larry Farnese and Shirley Kitchen.

Jacqueline Perez, 33, who has four children attending Ferguson, said she hadn't heard about the bill and wondered how she could take advantage of it if it is approved by the House and Corbett.

"This school is no good," the single mother said as her three sons and daughter sat on the steps after dismissal yesterday. "If I was able to, I would put them somewhere better."

If the bill passes, school districts would be required to notify parents in qualifying schools and post the list to their websites.

As he picked up his nephews, ages 5 and 6, from John F. Hartranft Elementary School in North Philadelphia, another school on the low-performing list, Hiron Allen, 20, said he wishes vouchers were available when he was in school. He said his sister would take advantage of them for her children, though he called Hartranft a "decent" school.

"If it was a better school, of course she'd take them out," he said. "I see it as a great opportunity."