Along with their mother as well. A titanic body with one of the most powerful and versatile devil fruits she uses creatively, plus a super scream, plus very strong haki, plus an interesting goal and dream and backstory; Big Mom had some insane potential both as a character and as a fighter.
Yet Oda ruined all of that, with some of his very worst writing in the entire manga.
There are also the non-Charlotte Big Mom Pirates such as Tamago who seemed to have lots of influence and respect within the crew and has one of the most unique devil fruits in the manga, Bobbin who was shot right after revealing his power, which surely had lots of potential (imagine all the possibilities with a sleep df) and seemed to have a particularly close relation with Big Mom, or Streusen who is Big Mom's father figure and surely the closest thing to King of Hearts for her as well and was said to be powerful and whose df has lots of potential as well, who were severaly underdevelopped and neglected. And there was that huge mess with Pekoms.