Help! Accidentally removed teen from Find my Friends...and it's prom night!!

I keep tabs on my teenage daughter using the Find my Friends app, and the Find my iPhone app. I accidentally clicked "remove" on Find my Friends, thinking I was removing the notification that I had set up for her, and it deleted her from that app. I went to Find my iPhone then to make sure I could still keep track of her until I could fix the other app, and it showed her phone as online, but not transmitting location, and I set up her phone to share her location. Why did a change in Find my Friends affect settings in iCloud Family Sharing? I even tried deleting the Find my Friends app and reinstalling it, because when I first installed it she popped up automatically since we are in the Family Sharing, but it didn't work. What can I do to fix it quickly? She has prom tonight, and I NEED that feature back ASAP!! Thanks!