you should read the last recent chapter properly. she clearly stated that she does miss lex but she is well aware that lex is just a part of him. thats is why the name she wished out for isn't lex but the duke himself.
She didnt ask for the magic to turn him into Lex. She didnt ask to be married to Lex. It was Lex that made her marry him, even going on a hunger strike. And she didnt ask to fall in love with Lex when he showed her all his endearing sides. But now that the original duke is back... its just sad for her also. Not seeing the one that loves her, even tho its the same person. and even being treated coldly. And she's stuck with it, not being able to say anything about it cos of her marriage to him and cos she loves him too much to leave him. And what irks me is that her concerns are downplayed as comic relief. That wish on a boat wasn't a personality changing spell that happened in the start of the manhwa. The boat scene was a wish. Like how you'd wish on a moon that your crush would like u back. A spell to make them notice you, but Not changing your crush into a whole new person that loses all memory of his old self. She wanted the duke to still be affectionate (even if it isnt as romantic as lex). Because just think about it, its really painful for her, to have someone making her love him... and then the next moment the spell wears off, all his love fades away, and even not thinking twice about pointing a sword at her or harming her hair (even if he did regret it, its pretty clear that his love for her is still not enough to ease her pain). So she is wishing for TRUE love. Not the Lex kind where it was just forced on the Duke. But the Duke genuinely noticing her and treating her kinder and u know, making living with him more bearable, and u know, she still thinks he wants to kill her so... she's also afraid of that. And she also lacks self esteem, considering how everyone from the higher social circle chides her for her background and also her appearance... so i guess she's quite desperate to turn to wishes.
when you know someone accidentally fell in love with u by some sort of magic u try to umdo it and free that person but she trying to find a spell to make it last? now she even feels "sad" when lex isnt there? uh that wasn't real he wasn't real wtf or u on about. do u expect hi mto live not as his true self for the rest of his life just so u can bd safe? how selfish cna u be. ugh i wana puke