Sam was glad Brian didn't overreact at the revelation of the many lies Desmond and Sam told him. Brian's reaction was the exact opposite of what she expected. It reminded her of how nice he was. Underneath his materialistic and womanizing attitude, he had a nice personality.
Now that she had successfully invited Brian, she went to the next person on her list, her mother. Normally it would be the first, but she made an exception due to how busy Brian was, not to mention the fact that she had already called and told Gloria on the phone about the proposal and her traveling out once everything was settled. She had yet to officially invite her to the wedding.
She decided to do so personally. She asked Desmond for Gloria's address, and unlike before, he immediately gave it to her. The contract was as good as void now that Desmond had all but admitted his love for her. She could now freely see her mother any time she wanted.