PHILADELPHIA (CBS) — Turbulent times continue for Philadelphia’s School Reform Commission, with the resignation of yet another member.

Denise Armbrister is the third commissioner to resign in the last month, following harsh criticism of the SRC over the expensive and scandal-tinged firing of Superintendent Arlene Ackerman.

Armbrister sent a resignation letter to Governor Corbett, who will have to nominate a replacement and submit the name to the Pennsylvania State Senate for confirmation. Education Department Spokesman Tim Eller says Armbrister’s term was set to expire in three months, and she hoped to speed up the appointment of her successor.

“She wanted to step aside now to help enhance the orderly transition for the new SRC member and the new leadership of the school district,” Eller says.

The SRC is still awaiting Senate confirmation of a commissioner—nominated in June—who will become Chairman.

Armbrister released a statement saying she hoped a faster, coordinated transition will allow the commission to focus on the district’s students.

Reported by Pat Loeb, KYW Newsradio