I am new to writing and this is my first story. I want to make my story believable and was wondering if one book is long enough to make my character fall head-over-heels for someone. She has known the love interest for quite some time but didn't think much of him because she was in a relationship with someone else. She breaks up with the previous guy because she is dealing with trauma, and then falls in love with the current love interest.
I don't plan on her realizing her feeling for him until the last book. Will one book be enough for her to go from liking him to being head-over-heels in love with him?