Her abilities basically equate to being a peak human athlete, with survival skills and great combat abilities (think Tarzan, but female). She has encountered a number of well-known characters, such as Wolverine, Daredevil, Spider-Man and Black Widow. As for her costume, it's basically a ragged bikini made up of materials you'd expect to find in the jungle.
Also, like Nightwing’s booty, Power Girl’s boobs have been the subject of many, many in-continuity jokes. From characters shaming her for her costume to Power Girl even acknowledging the fact that most males tend to look down at her chest instead of up at eye-level. No matter the controversy surrounding the infamous boob window, in many readers’ minds, Power Girl is defined by her chest. Hopefully, at some point in the future, she will get that chest symbol that she has been searching for.
She has continued to give people a reason to make her the subject of discussions everywhere, from trying to break the Internet with nude photos, performing every cosmetic procedure out there, and even marrying Kanye West. However, despite having haters everywhere, we can all confess that those cosmetic procedures have definitely paid off and she looks amazing.
In the late 1960s, Marvel wanted to make sure it got control of the name "Captain Marvel" for trademark purposes, so Stan Lee and Gene Colan quickly came up with a character to go with the name. For the costume, creators had him wear a literal Kree captain's uniform, which in this case was a green and white outfit with a little flair to it. It was a decent enough costume for a rank and file character, but it was a weak design for a superhero. Unsurprisingly, the Captain Marvel series was a hard sell for Marvel. Marvel needed to keep it going, though, so the company brought in Roy Thomas and Gil Kane to revamp the series.