It's probably the best known secret conspiracy among DC Comics fans - or at least the Arrowheads - on the Internet. You can find a dozen references to it on other sites, but the original page is long vanished into the Ether.
The idea had been suggested repeatedly, both as a joke and in all seriousness. From Cissie King-Jones' first appearance in Impulse and all through her time in Young Justice, the question was asked; Is Arrowette is yet another of Oliver Queen's bastard children? And the discussion might have just stayed there; a joke or something just tossed about by die-hards had it not been for one man; Scott McCullar.
Possibly the greatest scholar of Green Arrow trivia there is (and if he isn't, he certainly has the best resume out of all the contenders) - Scott wound up producing a theory... a conspiracy theory... that not only was it possible for Oliver Queen to have been Cissie's father but there was an evidence chain in numerous old stories which made it highly probable.
The exact details and issue numbers aren't important. For my purposes, the general details are enough to build a story on. I mention this in order to credit Mr. McCullar for a fine bit of detective work, because without that theory, I wouldn't have had this idea to work with.
Bonnie King operated as Miss Arrowette as Ollie was just starting his career as Green Arrow. Ollie quickly figured out who Bonnie was since she was the one person in the world worse at hiding a secret identity than he was. He told her that he knew the truth, revealed his own identity and suggested that the two of them could be a good pairing... in more ways than one.
The two did date for a time, but the relationship went south after Ollie tried to talk Bonnie into retiring from the crime fighting game. He suggested this partly because she more interested in fame and fortune than helping people and partly because she was a poor student, who refused to follow his directions and whose trick arrows were a joke at best and a hindrance at worst.
It wasn't until a month later that Bonnie realized that she was pregnant. Too proud to ask Oliver for help and not quite unwilling to air her own dirty laundry in order to embarrass him with a scandal, Bonnie entered into a quickie marriage with Bernell "Bowstring" Jones; a news reporter who she knew had something of a crush on her.
Eight months later, Cissie King-Jones was brought into the world and all was, if not happy, than peaceful for a few years. Bonnie was still upset by what she saw as a betrayal when the man she loved and idolized all but forced her out of the hero business. And that upset became bitterness when she developed severe carpel-tunnel syndrome and was forced to quit archery - even as a hobby - altogether.
It was at this time that Bonnie began to look at her daughter and see a way to recapture her old glory days - she trained Cissie with the bow as best she could but it wasn't until Bernell passed on (something about tainted shellfish and an allergy) that she was able to pursue the plan fully. Without another parent to object and the money from the settlement over the tainted seafood, Bonnie was able to buy a full complement of trick arrows and a costume for her daughter.
It was then - with news of Green Arrow's death having reached her and of a new Green Arrow taking his place - that Bonnie set about trying to reclaim the life she wanted for herself through her daughter's career as a vigilante. Sadly - or thankfully, depending on your point of view - the new Arrowette's career proved to be even more short-lived than her mother's, as a concerned hero (Max Mercury) took action, seeing signs of Bonnie's derangement even then. He called Child Protective Services and Bonnie was arrested on charges of child endangerment.
Cissie herself was handed over to the St. Elias School For Girls and that might have been the ending of things had a talk with a counselor not convinced Cissie that she could still be a hero without following the path her mother dictated for her. Sometime later, Cissie would fall in with Young Justice and the rest is history.
(Just so we're clear, I don't intend to rewrite any of Cissie's history regarding Young Justice. I don't need to.)
Even after striking out on her own, Cissie's career as a hero was brief. She retired after nearly giving into her rage and righteous anger, nearly killing the man who killed her counselor. She still remained close to her friends in Young Justice, however. And she still practiced her archery, going on to represent the United States in the Olympics. She won the Gold, of course.
Now, with a string of endorsement contracts giving her savings enough to go to the college of her choice without scholarships (she's been offered a slew-load of athletic scholarships, of course) and take care of herself and her mom for the rest of their lives, Cissie wasn't feeling much motivation to go back into the heroing business... despite the best efforts of her classmate and best friend Cassie Sandsmark trying to talk her into joining The Teen Titans. No, Cissie wasn't feeling much motivation at all... until her brief stint in the Borrowed Time Timeline.
And now she's wondering what she's missing out on being retired. She's wondering if there's a place for Arrowette in the world again. And she's also wondering if what she remembers of that universe is true and if Oliver Queen really is her biological father. She took a month or two to mull this over and then returned to Star City to confront Oliver regarding his past with her mother.
Ollie, for his part, admits to the possibility given when she was born and is more than willing to submit to a blood test. Cissie, for her part, is a little nervous about the truth. As much as Ollie being her father would explain a lot of things (her temper and a natural talent for the bow that exceeds her mother's), she does feel like she is betraying the man who raised her somewhat by trying to investigate the matter.
The End Result? Oliver Queen is indeed Cissie's birth father. Ollie, for his part, offers Cissie whatever support she wants and needs. Cissie, for her part, notes that she is having a hard time accepting this and is going to need some time to process things. It's an awkward situation all around.
And then Roy says "So... are you going to be Cissie King-Queen now, or what?"
And somehow, the ensuing groan from all assembled makes the awkwardness a little more tolerable.
Cissie and Ollie: Awkward City, at first. Roy quips that you'd think Ollie would be used to this sort of thing by now but... finding out you have a kid you never knew about is never easy - especially for someone like Ollie who places such a strong value on family. Neither he or Cissie is quite sure exactly how they should feel about one another but both are slowly reaching for trying to find some common ground.
For Cissie's part, it's weird trying to reconcile the way the world views the legendary Green Arrow, what little Bonnie has said about him and the idea that this man is her father. Ollie, for his part, is willing to give her all the time and space she needs, noting that from what he's heard about her career as Arrowette, he couldn't have trained her better personally. That praise will start to chip away at the wall - but anything resembling a close student/mentor relationship is a long time in coming.
Cissie and Dinah: Not surprisingly, Cissie will wind up bonding more with Dinah than anyone else in the family at first. Dinah can sympathize with Cissie's homelife, having grown up the daughter of a heroine herself. And yet, they couldn't be more different since Dinah had to fight to claim her mother's legacy whereas Cissie had a legacy thrust upon her. Still, the Mama Bird's maternal instincts will win out as she tries to make a little more room in the nest for Cissie.
Cissie and Roy: Neither of them is likely to be around very much but Roy will be quick to welcome Cissie with the same older-brother teasing treatment that he gives the rest of the family. She'll take this as mockery at first but will eventually start responding in kind - sneaking a shampoo arrow into his quiver.
Cissie and Connor: Connor probably grows the closet to Cissie out of anyone in the family... both sharing a legacy of a father who had no hand in raising them. Connor offers Cissie the two things nobody else in the Arrow Family can really offer regarding her situation; complete understanding and a truly sympathetic ear.
Cissie and Mia: Good Daughter/Bad Daughter sibling rivalry. As Cissie comes around to joining the family, she'll become a little jealous of the closeness that Mia and Ollie share. Mia, for her part, will be a little defensive about the prettier, more athletic, world-famous "new sidekick" hanging around... but it will become a friendly rivalry, sooner or later.