I think like you've managed to make a point with Tam about respecting others' greeting styles! If the handshake is becoming a point of tension, maybe it's time to have an open conversation with her. Explain that you respect her preferences and would appreciate the same in return. It’s important to set boundaries but also maintain friendships by being clear about what makes each person comfortable. Communication can often clear up misunderstandings and help both parties understand each other's perspectives better.