The scene goes like this. Takada and Tetsuya are talking about Reiko possibly having romantic feelings towards Tetsuya. Tetsuya says there is no way this is true since she flat out rejected him before (but the truth is that she rejected him because of her extremely ツンデレ-like character, plus she felt a certain social pressure since he is a "common man" and she is sort of like an お嬢様).
Takada responds :
(rough translation) Tetsuya, I like how straightforward you are. But people aren't always so logical. I think even Reiko-chan is 健気 to a person she's in love with. She just doesn't know how to express that love.
And after that Tetsuya thinks to himself:
I'm having troubles grasping the exact meaning of 健気 here. From reading definitions and some articles I understand it has to do with her caring about him very seriously (and it also means that this attitude of hers is admirable and worth praise?). But I'm not quite sure why Takada uses 健気 here to convince Tetsuya, and I find difficult to put it in English words in a way that would sound nice.
What would be a good way to translate 健気 here? Would I need to restructure Takada's speech to convey the idea better?