Katie McBain was a rape victim who Dr. Samuel Beckett leaps into in the Season 4 Quantum Leap episode "Raped" (#4). The part of the leapee played was by Cheryl Pollak.
Katie was raped by a guy she was dating named Kevin Wentworth. They were on their third date when Kevin forced himself on Katie after she turned him down for sex, raped and beat her. Sam leaped into Katie just after she'd finished being examined by a doctor. In the original timeline Katie didn't charge Kevin and left town a week after the rape and never returned, even for her dad's funeral eight years later. Sam decided he had leapt into Katie to ensure Kevin was charged with the rape. He was, however Sam didn't leap leaving him to realise he had to ensure Kevin was sent to prison. While waiting for trial, most of the town turned against Katie as the Wentworth's were highly respected for their high standing and charitable donations. They believed Katie had sex with Kevin then cried rape when she regretted it.
The trial arrived and Sam told Al he couldn't testify as to what happened since he hadn't been there and told him the only way was to bring Katie into the Imaging Chamber and find a way to let Sam hear her. Just as Sam took the stand, Al was able to bring Katie in and she accurately described the attack. However her testimony wasn't enough to convict Kevin and he was found not guilty.
That night, as Sam and Al wondered what Sam was there to do, Kevin confronted Sam and punched him, furious that 'Katie' had put him through the trial. He made it clear he'd raped her and was ready to do it again, however Sam recovered and realizing why he was still there gave Kevin a throughout beating as revenge for what Kevin did to Katie. Thanks to this, he had restored Katie's confidence and exposed Kevin for the monster he was, and with that Sam leaped.