Is Maria stupid why would Bianca kill her mom to keep her in check when she wasn’t compe...

Is Maria stupid why would Bianca kill her mom to keep her in check when she wasn’t competion in the first place like he never even looked at you and Bianca even gave her chances to steal him I’m soooo confused like the prime suspect would’ve been the step mom anyway it’s just to obvious that Bianca is getting framed cause I fear she would’ve covered it up a bit better or went for Maria directly if any of that was true. I hope the MC never forgive Maria for this