Harley Quinn has become one of the biggest characters in DC comics. As her popularity has increased, so has her capacity for doing good, as she's become a full-blown superhero. From rescuing animals in trouble to freeing the Lowlies of Apokolips, Harley has done a lot of good.
Even when Harley was more villain than an anti-hero, she was still showing her potential for doing good. However, it's thanks to her second solo series that Harley had a new, Joker-free lease on life and viewers saw her become more of a "Good Guy" hero.
10 When She Helped Selina Kyle Get Her Revenge On Hush
As part of the "Batman R.I.P." and "Heart of Hush" events, Hush had removed Selina Kyle's heart and had put her in grave danger so that he could get to Bruce Wayne. Hush is ultimately defeated but manages to escape, something that doesn't sit right with Selina as she wants her revenge to hit him where it hurts: his bank accounts. Selina recruits Harley to actually steal Hush's money which she does with glee. Harley was a villain, but she did good by her friend.
9 When She Rescued Batman During The Joker War
After her previous showdown with Joker's new sidekick, Punchline, Harley had had her throat slashed and it looked like she was done for. She miraculously shows up to rescue Batman and in Batman #98 by James Tynion IV and Jorge Jiménez, Batman is incapacitated and recovering from Joker's toxin in Poison Ivy and Harley's secret Eden.
When Punchline arrives to take them both out, Harley does all she can to protect the unconscious Dark Knight as she fights her replacement in a Round Two match.
8 When She Brought Black Canary Some Thoughtful Baby Gifts
In the Injustice comic books, the bond that Harley Quinn develops with Black Canary is a surprising delight in an otherwise dark series. When Harley and Dinah have their big fight, Dinah is overcome with morning sickness and asks for a quick break, Harley almost immediately understands that Dinah is pregnant, and they talk instead, becoming friends. When she gives birth, Harley is the one to bring a menagerie of gifts for the baby, including a muzzle, just in case he’s inherited Dinah’s “Canary Cry.”
7 When She Teamed Up With Wonder Woman & Batman To Take Down The Batman Who Laughs
After being convinced by Jonah Hex, Harley decides to join Wonder Woman and Batman in their fight against "The One Who Laughs." Their team travels to the dying star that Superman and the rest of the superheroes are imprisoned on, and manage to rescue everyone, including their secret weapon: Jarro and his incredibly powerful psionic powers. Harley and Jarro develop a friendship as Jarro rides on the dusty cowboy hat that Harley wears (a memento from the late Hex). In this event, Harley’s a fully-formed hero.
6 When She Used Her Powers For Good In Coney Island
While Harley doesn't technically have "superpowers" she is still a formidable supervillain and, as shown in Harley Quinn Vol. 2 #14 by Amanda Conner, Jimmy Palmiotti, and Chad Hardin, she now chooses to use her skills to help the little guy, be it an old woman getting attacked by a biker gang or one of her patients at her new job as a therapist at an assisted living home. While Harley still can't help but get herself into mischief, her goodness shines in this issue.
5 When Her Team Rescued Wally West In Heroes In Crisis
After it had been revealed that both Harley Quinn and Booster Gold were framed by Wally West for the murder of several superheroes, the two teamed up with Batgirl and Blue Beetle to rescue him as it became apparent that, while Wally was the perpetrator, he was also a victim in the events of Heroes In Crisis. Despite Wally having been the one to kill Poison Ivy, Harley looked past her own feelings and worked to stop him from doing harm to others and himself.
4 When She Chose Her Daughter's Well-Being Above Everything Else
In the Injustice series, Harley Quinn revealed to Black Canary that she had become pregnant with Joker’s baby and had disappeared for a year, not wanting him to know that he was a father.
After giving birth to her daughter Lucy, Harley sent her to live with Delia, Harley's sister. Since Harley was planning on returning to Joker, giving up Lucy was the best thing she could have done for her, showing that there was good in Injustice Harley before she turned a new leaf.
3 When She Rescued Nathan The Dachshund From His Horrible Owner
In Harley Quinn Vol. 2 #1 by Amanda Conner, Jimmy Palmiotti, and Chad Hardin, Harley is on her way to Coney Island to begin her new life. Harley waits at a red light as a hipster man uses the crosswalk in front of her, not caring that he's dragging his poor little dachshund behind him. Harley sees how sad the dog is and she takes matters into her own hands: with her bullwhip, she frees the dog and drags the horrible owner behind her motorcycle.
2 When She Rescued Her Suicide Squad Brethren From Basilisk
In Suicide Squad Vol. 4 #16 by Adam Glass, Henrik Jonsson, and Sandu Florea, Deadshot wakes up in an infirmary and still alive despite shooting himself in the chest in an earlier issue. Amanda Waller tells him that he, El Diablo, and Iceberg were rescued from the Basilisk compound they were being held in because Harley had refused to abandon them. Harley was on a mission to recover the other members of the Suicide Squad and she even went up against Grey Lora all alone.
1 When She Saved The Lowlies of Apokolips & Helped Take Down Granny Goodness
In Harley Quinn Vol 3. #47 by Sam Humphries and John Timms, Harley is on Apokolips and, thanks to the cruel Granny Goodness, has become "Hammer Harleen" and a member of the Female Furies. Harley is ordered to take down a “Lowlie” named Petite Tina but, when Harley saves another Lowlie in the middle of the battle, Tina reveals that she is a former Fury and that the two of them could be allies. Harley and Tina free the Lowlies and takedown Granny herself.