Some of Bruce's blood gets into an open wound of Jen's in the aftermath of a car crash, which gives her powers. It isn't as dire as Walters getting into a car crash by herself and receiving a transfusion, but it helps explain why Banner is such a huge part of the series.
There is a lot of metatextual fourth wall breaking that Attorney at Law will play with in its comic books. This is a joke that has been around for a long time. Since it was first introduced, there has been a lot of over-explanation, including a retcon of the choice that described the fourth wall breaks as a "metafictional superpower".
She-Hulk: Attorney at Law will premiere on Disney+.
Do you want to know more about io9. House of the Dragon and Lord of the Rings: The Rings of Power, as well as what's next for the DC Universe on film and TV, can be found on this page.