Why do I get random notifications from a friend on Facebook?

[john]

Every time she posts a status update, I get a notification and NO she is not one of my "close friends" so I shouldn't be seeing notifications.

[Vo Danh]

Maybe she subscribe you as a close friend or she may try to spam your wall (you know, there are many games on fb that require you to post, for example 50 posts on your friend walls).
So try to ask her did she accidentally post it or it's a spam bot.

PS:
Oh yeah, there are some apps that act like a spam virus when you access it with your fb account. Once you've used the apps, it will automatically spam your other friends' walls