- The twins and all their friends and family (and their friends' family) are described as being unrealistically beautiful, without them suffering from bad skin, weight issues, greasy hair, body odor, and other typical teenage problems.
- Alice Wakefield being mistaken for the twins' older sister, despite one child being in college and two in high school (and, I'm just adding this : the fact that Alice and Ned's wedding was in 1963 ---> Check Wikipedia), which would place her in her mid-to-late forties.
- The character of Margo Black looking exactly like Elizabeth and Jessica, to the point where she could fool their own mother, Alice. (To see more on Alice, look at the above point.)
- The obvious lack of ethnic groups in Sweet Valley, as the majority of the characters are white.