Gloria burst into tears!
She couldn't control herself!
She thought that even if she could not forget her father's death, she could stay calm when she faced it, but she never expected that she would hear her father's voice again.
Her father must know her uncle and his family's wild ambition and be extremely disappointed with them, but he didn't want her to avenge him or know much about the inside stories. However, he had to remind her to be careful in case her uncle and his family would hurt her.
Declan was Gloria's father.
He knew that Gloria was smart and she would know what was going on after hearing what he said, but he didn't want Gloria to take revenge, so he could only say those things.