Waiting in the Wings (Zipp Storm x Fem Reader)

As a way to seal peace once and for all between the kingdoms and the different breeds of ponies, your uncle offers your hoof in marriage to one of the daughters of the Queen of Pegasus. Despite disliking arranged marriages, but at the same time wanting the good for all realms, you passively accept the union in matrimony.
On the other hand, your fiancée doesn't accept the proposal at all and does everything to avoid it. Until the day that her younger sister Pipp, falls seriously ill because she doesn't want to get married.