It's difficult to explain, because the love story is important to the plot, but it doesn't control the plot. Foremost, it is a fantasy-adventure novel, with romance coming in second place. I don't know if this helps at all.
The "love story" was pretty unconvincing, boring, and not done well. It doesn't take up much of the book. What does take up most of the book is the self-loathing heroine's constant harping on how she isn't good enough.