Spoilers ahead:
Honestly, I spent a lot of the book confused by the FMC's confusion. She is engaged to a man she doesn't love for reasons and both her and her fiance are aware it's a marriage of convenience. He knows she's doing it for reasons that have nothing to do with love or wanting a life with him.
Despite this, the FMC is in a state of confusion as to how she can be engaged to one man and feel attraction/deep feelings for the MMC. Ummm... Shouldn't it be obvious? She has no emotional ties to her fiance. None. Zero. Zulch. When she wonders how she can feel attraction to another while engaged to someone else, it gives the feeling of someone conflicted because they have actual romantic feelings for two men. But that's not what's going on here.
The FMC also, upon finding herself in the middle of an intense connection with a handsome, rich man, is forcing herself to remain resolute in her plan to marry someone else for money. Someone she doesn't love and isn't attracted to. Why? No one knows. She makes sure to tell the MMC that she still plans to marry her fiance, but given the intense connection/feelings that are portrayed on page, it would make sense that she tell him WHY she's making that choice despite their connection. Who knows? The rich man she has a connection with might help out so she doesn't have to get married to someone she doesn't love. I'm not suggesting she use him but she should at least give him the benefit of the truth, in the face of such feelings. (She does eventually tell him but has to be asked by the MMC.)
Then, the man she has a connection with tries to call her all week and she doesn't answer because of assumptions on her part even though she's taking the leap and marrying the man she doesn't love that very same week. The last conversation they had, the MMC said he was going to research ways she could potentially get OUT of the marriage and yet, she doesn't answer his calls? Because she assumes he might be with someone else? Even if she believed he was with someone else, at the very least, he might have found out something that could help her avoid a loveless marriage.
Finally, the MMC saves the day and tells her the truth about her fiance and, yet, she still refuses to speak with him in private so he can explain the misunderstandings regarding him being with someone else. Again, she's going off assumptions on her part and he's JUST followed through on what he told her about finding a way for her to get out of her marriage.
The FMC makes no sense this entire book, and for that reason, it was difficult to get into the story. I didn't root for her and felt bad for the MMC. I'm rating this two stars because I use different rating standards for Harlequin category romances due to differing expectations for them versus other books.