I really liked this manhwa at first and the ml and fl but I'm getting annoyed by her that ...

She does feel quilty though, she states that several times throughout the story.

but she still has no intentions on telling him as what she talked about before with the real charlotte

I mean, it’s understandable as to why. She didn’t know that he knows she isn’t the real Charlotte. She probably thinks that if she does tell him, he’d receive it poorly. Perhaps in the future there might be a chance to tell Lancelot, but for now I think she’s much more concerned acting like the real Charlotte and preventing Lancelot’s death.

But didn't lancelot die because the novel charlotte wants to take revenge on the duke so long as she doesn't take revenge lancelot wouldn't die since she's in the body of charlotte. I actually don't mind her not telling him the truth if their relationship were to remain as butler and the lady but not now when she decided to marry him and have a romantic relationship with him

This is called the war between your inner self. She can't bear to tell him, afraid all the happiness now would pop like a bubble. She is trying to strengthen herself to tell him but ends up procrastinating it.

Sometimes people with these anxieties tend to just leave it till the cat gets out of the bag itself and just immerse themselves in the current happiness(while they still can). Some of them ends bad and some of them end nicely. Some of those bad ones were able to redeem themselves.

Well, at times, people just can't help themselves and caved in to their desires. (￣∇￣")

I just wish she'd tell him very soon if i may be blunt she's selfish acting like the real charlotte and flirting with her beloved character and marrying him yeah she do be having a hard time too but she still enjoying and indulging on it so much i really liked her at first but now I'm just annoyed at her until she tells him the truth

Hmm.... I honestly don’t mind because what else do you do if your favorite character is right in front of you? It’s normal for her to flirt with him, she cried when he died and was rooting for him until the very end. She ws his fan as well.

Though ngl the pacing is a bit slow, hopefully they get on with more pressing matters as I too would like to see her tell him that she’s not the real Charlotte. And how the real Charlotte would react.

Afaik there was a spoiled abt this. I suggest hitting up NU if you’re interested hiw everything pans out

The word is “didn’t” but that doesn’t mean he wouldn’t. Also, you forgot that the MC didn’t know that. She transmigrated thinking she has to save her favorite character, then get these scenarios shying away from the novel plot. However, there’s a bigger threat like the demon who knew about her and Lancelot plus the OG charlotte and duke as well. I think it’s natural to think “the plot diverted everything is uncertain let’s try and survive”. There are too many unknown factors to consider and since the plot diverted she doesn’t know if Lancelot will die still.

6 dislikes ヾ(❀╹◡╹)ﾉ~

Idk why but OK (︶︿︶)＝凸

I understand your pov but also I agree with the MC. She read the novel and knows that he is (or used to be) beyond in love with the original Charlotte. He lost his mind because of her and she was basically his reason for existing.
Telling someone like that "oh hey, I'm not her. I'm possessing her body ". At this point it's not just about her being isekai-ed here. It's about her possessing the woman he loves, the woman the MC read details about in the novel. So she probably fears his retaliation not just fearing for her and his safety but also her heart breaking. She is so much in love with him and if he rejects her she'd be devastated.
Well, we all know none of that would happen but she doesn't.