Everyone who has come to visit Amelia has blamed her for everything, they've all insulted and bashed her. She was ready to take the next insults from her sister, she deserves it though, what she did was inhumane.
She cared less about what others said or thought of her, what she just couldn't take was the fact that her family had abandoned her. Amelia felt alone and dejected.
If she ever gets out of this place alive, she'd be sure to take her own life herself, she doesn't think she could live with herself after everything she's done. Her existence alone was pain to everyone, no one wants her now, not even her family members. Her family is better off without her, they've lived happily before she arrived. Her arrival was meant to be a blessing, but rather it became disastrous, destroying her life and that of her family members too. She was just too toxic to be close to anyone.