A report in the Pittsburgh Tribune said attacks were also launched on the Catholic diocese and the Westmoreland county administration.
Michaela Gabriela King came up before a judge last week who released her on a signature bond.
Investigations were kicked off after the supervisor of technology at the school notified authorities that since 31 October the computer system in the district was coming under DDoS attacks.
King used the BetaBooter program to launch the DDoS attacks.
In an affidavit of probable cause, Murrysville patrolman David Hanko and county detective Paul Burkey said King had admitted to carrying out the attacks, paying for BetaBooter out of her PayPal account.
They said when they asked her if she considered herself a computer genius, King answered in the positive.