Well, this Lois still has Claude in her background. And Paul as well, I assume. Not to mention her father.
But something must have happened with Chad as well. Otherwise he wouldn't be included in so many flashbacks. And I have to wonder what that might be. Was it really big? Or was it something that wouldn't seem so big normally, but would seem big to Lois? After all, if I read correctly, she had been with Chad since Middle School and was still with him when she was applying for college. Any kind of break - up like that would hit her hard, especially with her background.