For a moment, Tifa had hope that Sora would agree with her. That someone could be sent to find Riku, and gently dismiss him. Tell him that Sora loved him, let them cry, and then they'd go their separate ways.
But then Sora laughed and her hopes died. She could at least tell her husband that she tried.
"I suppose I am not the only one," who would have to accept Riku. "I will bring you that tea you asked for." She got up, and then paused. "No matter who you choose, Sora, I will always love you. And when you make your final decision, I will do my best to support you, and welcome your choice into our family. Your grandmother was not so kind to me, and I would not wish to repeat that for anyone you wed."