The correct answer is 2-The girl was conscious of her mistake, but she still needed to follow through with her original plan.
Step-by-step explanation:
In the original sentence, the word "conscience" to describe the girl is incorrect because this word is a noun rather than an adjective (a word that describes something or someone) and it refers to the general sense of awareness, Due to this, this word should be replaced by "conscious" which is the adjective to show the girl was aware of her mistake. On the other hand, the expression "follow threw" is incorrect because the grammatically correct form for this is "follow through", which means to continue a process or action through difficulties or problems. This makes option 2 the correct option.