Like his parents are both human mutates who weren’t pregnant at the time of their origins into the fantastic four so how is Franklin not a mutant or his sister?!
Neither is peter parker but his kids are considered mutants including his second son who is already exhibiting powers and considered to become more powerful than peter. So what makes valeria and franklin any different? Just cuz there powers are more powerful? There are other mutants whose powers developed at an earlier age i dont know everyone but i believe hope summers was one