Yeah i know all that, but the thing is Women in this World are more powerful than Men in general than the strength difference between them in our Earth, especially because of their Magical abilities which Men totally lack, and this Magical ability greatly boosts the physical abilities of a Women.
While i do agree with the situation you presented, i doubt it would be such an easy situation, unless White Worm was born a lot weaker than typical Women of that world. And considering that people know about her past of being abused by her Father, i doubt he could have played the "i am weak man" card.
Not all abuse is physical - even in our world, "she was abused by her father" does not necessarily mean "her father beat her". In context, it's far more likely that her father was
emotionally abusive, using the authority he had as a parent to belittle and control her while isolating her from friends or outside support. Being physically and magically stronger doesn't help in that situation, because any retaliation can be used by her abuser as evidence that
she's the bad guy, turning everyone else even more against her and making it even harder for her to get emotional support. At that point, all you can do is either keep your head down and hope that if you can go long enough without rocking the boat, people will begin to believe your side of the story, or say "to hell with it,
let me be evil then", which is how we get the White Worm we see here.