Undo "marked as spam" on Facebook Messenger I was texting with my friend, but I didn't lock my keyboard. I marked her as spam. Do you know how I can get back notifications from her messages?
I'm not exactly sure what you mean by 'marked as spam' since I can't see this option in either the Facebook app or the Facebook Messenger app. I'm assuming you mean you turned off notifications for her messages since you mention you want to get them back. I'll explain how to turn them back on.

Facebook Messenger 


Open up the conversation with person
Press the 'i' in the circle in the top right 

Click on Notications and set to 'On'.


Facebook App


Go to your messages and open up the conversation with the person.
Click on the gear icon in the top right 

In the Settings tab make sure 'Alerts On' is selected.