What is the ruling on inciting a fiancée to break off engagement with her fiancé?

Islamic law prohibits inciting a fiancée to break off her engagement with her fiancé if he is a suitable match and the engagement has already taken place.

However, if the incitement is due to the emergence of faults in the fiancé that make it advisable to end the engagement, and the intention is to offer sincere advice (nasiha), then there is no objection to it in Islamic law.

And Allah Almighty knows best.