Another day had passed after a good night's sleep, and Eliza was still insisting on her accusations, and Mathew believed her. He, like Eliza, had noticed the smirk on her face, and it was clear that Aurelia was tormenting his mother.
She was the only one who held such a grudge against his family. She had murdered his sister in that manner, and there was no way to prove it. He had his people investigate her movements during the week she wasn't in Athalia, and to his surprise, she didn't go anywhere or meet anyone of significance. It was truly shocking to learn that she had been poisoned and had to stay in the hospital.
Even if they suspected her, they needed evidence to convict her, so for the time being, he just needed to calm Eliza down and wait for the right time to avenge their loss.