Being made responsible for a dragon, while being little more than a child herself, had been difficult. She had learned that she had made many mistakes in his upbringing, and had been unnecessarily hard on him.
Things had changed in Ponyville, though not by much. She had tried to give him more space to grow into his own, and he had. She had expected him to become angry when she tried to apologize for her horrible parenting. But he had waved it away, telling her that she would always be his big sister
He truly had a heart of gold.