Gets treated like dirt and follows him like a puppy dog.
Actually, except for Merritt, all the girls were exceptionally insecure about needing men to validate them.
And I don't care if it was the 60s.
"What would you like to see on your honeymoon, Mrs. Cord?"
"Lots of lovely ceilings."
Merritt seemed very self-confident at first, but later it became clear that she wanted to have a perfect relationship with her new boyfriend. I think she knew that she wasn't going to make it through school, so marrying a rich guy would be the solution to the problem.
As for Tuggle, she eventually ditched her sweetie (who was treating her like dirt) and he came running to her. So she did show some sense eventually.
~~~~~
Jim Hutton (1934-79) & Ellery Queen