Yes, this nasty young woman deserves two SUTHs !

Elinor is shocked when Lucy marks out Edward to offer proof of engagemnt with a miniature and letter in his handwriting.

'her heart sunk within her, and she could hardly stand; but exertion was indispensably necessary, and she struggled so resolutley against the oppression of her feelings, that her succcess was speedy, and for the time complete.'
(ch.22)

The phrase shows a struggle at this point between the two forces Jane Austen singled out as important for understanding Marieanne- feeling and will.

Lucy's disclousure is a real test on both Elinor's sense and feelings. She must distinguish hope from the reality.
Elinor was mortified, it would be understandable if she'd given way to wretchedness, so I admire her self control.

Edward must've spoken to Lucy in glowing terms of the Dashwood girls, esp. of Elinor and stirred Lucy's jealousy.

Clearly, Lucy takes a sadististic pleasure taking Elinor into 'confidence'. She goes on playing a malicious game with Elinor providing detailed and self-flattering accounts of her relationship with Edward. (ch. 24) Yet in spite of provocation, Elinor reveals nothing.

I noticed the 'eyes' of Lucy Steele as well.

'Her sharp, quick eye'.

'Her little eyes full of sharp meaning'.

'eyeing Elinor attentively'.

I read in a literary appraisal St. Lucy is the patron saint of eyes, which I've been looking for.
Lucy's hard little eyes render such an idea into an absurdity.

Elinor noticed Lucy's poor grammer, which probably reflected on her ignorance and lack of education.
She also noted with less sympathy, Lucy's flatteries at Barton Park and her insincerity.