Tessa has always known she was adopted. But when she finally meets her birth mother, she is in for the shock of her life. Tessa has a sister too and the girls are identical twins. At first, Tessa is thrilled. Looking at sister Tammy is like looking in the mirror. But the twins soon learn they have little in common. Tammy is spoiled and moody. She hates her parents and she drinks--a lot.