a point to make, they two Corina and Avril are "step-sisters"
Avril had a happy childhood with her father-mother . her father was the one to marry into the family. and he remarried to Corina's mom after her mother's passing.
Avril learns that the family love wasn't true, but despite that, and no matter how much she tried- they refused to accept her into the family. step-mom despises Avril, Corina followed in her footsteps leading up to the servant dynamic and Corina's incredibly spoiled behavior. she learned to be high-handed without morality or remorse.
there was attempts on her grandmother's side to take her in, but it was brushed off by the 'immediate' family.
both her mother and grandmother who cared for Avril passed, and their possession were sold to fund the step-family's lavish lifestyle.