I certainly believe the theory that Big Mom could be an escaped test subject from Punk Hazard. Remember how over there kids were gigantified through experiments and given addictive drugs so they wouldn't run away? When they went through withdrawals they started hallucinating people as random objects and would become stronger and more violent until they got the "candy." Big Mom's parents probably rescued her and she had those "episodes" like she continued to have into her adulthood. Now I know that Caesar wasn't at Punk Hazard until decades after Big Mom's childhood but remember that the World Government has been trying to create their own giants for DECADES. That's one of the reasons why I feel bad for Big Mom.