Jenna Marshall

Jenna Marshall is the younger stepsister of Toby Cavanaugh. Jenna became blind because a prank played by Alison, intended for Toby. Jenna was in psychotherapy once to talk about Toby. The girls suspect her to be the mysterious "A". Before Alison went missing Jenna and her step-brother Toby were sexually active with each other. Before Jenna was blinded, she was a victim of bullying. When Alison discovered that Toby "touched" Jenna, she set the garage on fire with fireworks with the help of her friends. Toby admitted he set the garage on fire after Alison blackmailed him by saying that she would tell about his and Jenna's relationship. In the television series Jenna is in love with Toby, but he isn't in love with her. He never was, he just had a fling with her once, but she won't accept that. Jenna is very jealous when she discovers that Toby really likes Emily. In "Salt Meets Wound", Jenna tells Toby she turned him in to the police so he would come home and continue their relationship. She, along with a lot of other girls, were picked on and embarrassed by Emily and her friends.

Relationships
Jenna (in the books) did not like Toby as much in the show, because she was sexually abused by him the night of the "Jenna Thing". Alison saw this and dropped the fireworks on accident, not meaning to blind Jenna, but attempted to get Toby sent away. She and Jenna planned The Jenna Thing. In Flawless, she felt a little relieved after Toby's suicide.

Jenna (in the show) is obsessed with Toby, because instead of him sexually abusing her, they were sexually involved. She still loves Toby and whenever he is with Emily or Spencer or another girl, she gets jealous.

Ian
She is seen talking to Ian in "The Bad Seed" as if she knows, and is friends, with him.

Alison
Jenna reveals to the four girls that Alison became friends with her right before she died, and confided all her secrets in her. The girls are worried as to what Alison may have told Jenna. In the fourth book of the series, "Unbelievable", Jenna reveals to Aria that it was because her and Alison both have "sibling troubles".

Romance
Jenna is in love with her step-brother, Toby. Alison catches them touching each other before she sets the firework off in the garage. Toby is sent away because of this, and when he returns he is scared of Jenna. Jenna is seen picking out lingerie by the girls, and no one knows if it was for Toby, or if it was for someone else. It was revealed it was for Garrett Reynolds.

Trivia

 * Jenna had an affair with her step-brother Toby
 * She is rumored to be "A"
 * Paid Caleb to spy on Hanna
 * Was blinded by all the Liars (including Alison)
 * Was slapped by Hanna
 * In "Reality Bites Me", Jenna leans into her reflection in the elevator to apply her lipstick. She's supposed to be blind. This is possibly a deliberate error by the filmmakers to make the characters and viewers doubt that Jenna is blind.
 * Is alive in the TV series, but is killed in the books.