Jenny Quantum is not the latest in the Jenny reincarnation cycle, but an Alternate Universe version of Haruhi Suzumiya.It's stated in the comic that she is far, far more powerful than any previous Jenny. Anything pointing to her being a Jenny can be explained by the fact that she believes herself to be a Jenny, and thus has altered reality to fit that.
At the end of Watchmen Dr Manhattan says he's going to create some human beings. Jenny Quantum is one of these.Heck, it's not like Dr Manhattan couldn't cross the Bleed if he wanted to.
Dr. Manhattan split himself in two and became the Brothers from Marvel Versus DC.
Jenny Sparks was madder than the WeathermanWith all her protestations of not wanting to be involved, she built herself a pretty nasty powerbase before her end. Many powerful forces went dead or converted to her cause when she was around.
The Midnighter is Dexter MorganBear with me on this one. His entire memory was erased when Bendix finally sent the team on their first mission (which only he and Apollo survived), so we have no way of knowing Midnighter's history. In his solo series, it was implied that Bendix chose him because he was already a serial killer who was set off by some unbelievably traumatic event.