Remove Notify me settings in Find Friends

I have an issue with Find Friends App.

I setup a notification for when my girlfriend arrives at a particular location. This worked fine!

About a year later we broke up and we unfriended each other in the app. Sad, but life goes on.

Ever since then, I still receive notifications when she arrives at the particular location.

This obviously make the new girlfriend slightly annoyed.

Has anyone got a fix for me? And NO, I cannot friend her, remove the notification and un-friend again.