How to unblock someone on Facebook?

[Tanya]

A couple months ago I impulsively blocked a family member from seeing my posts. Unfortunately, I don't know exactly what kind of "block" I made. She doesn't show up in any kind of blocked list, and she's not listed under a group of restricted people when I post. At least, not that I can see.
Here's what I do know: she hasn't been able to see the posts I've made since late July, including photos I've been tagged in. She can message me and post on my wall, though. So, what did I do and how can I undo it?

[Michael]

Hey Tanya,
Did you just clicked on turn off chat for that member? If you have blocked it then they shouldn't be able to message you either.

If you have turned the chat off then turn it on and it should work fine.

Or go to setting and see under blocking - If you have blocked that person then you should be able to see his or her name there.