That's pretty weird, because my Lena is in relationship with Ian, got ensnared by Seymour, hooks up with Louise and Ivy, can't resist getting fucked by Axel, and she is still at Lust 7 by the time she leaves for train station, dressing considerably less provocatively.So I did a run through where Lena was a goody two shoes and didn't enter into any relationships, with the exception that she allowed herself to be completely seduced by Seymour.
That alone, and not doing anything else, was still enough to get her lust score high enough so that she was wearing the tan crop top, choker, and giant gold "trailer park trash" hoop earrings when she takes the train from her parents house to the beach house at the end of Chapter 12.
I get the feeling you are omitting some crucial details from the picture you've painted.