I need help with facebook customizing privacy settings please?

[flipflopchick]

I went into my privacy settings on facebook & blocked my mother-in-law from viewing my wall posts without un-friending her because if I un-friended her she would notice & probably get angry, but honestly I'm sick of her reading whatever I post & making little comments about it. I did this but I think she can still view my stuff, what am I doing wrong? Anyone who is really good at facebook privacy setting plz help. And yes if I cant figure it out within a day or so I'll probably just delete & block her, but I was trying to be nice about it.
Please dont say that its not possible because it is, I think its working but she can view everything up until the time that I blocked her so she can still read old posts which i dont like, and when I like another friends status that is showing up also.

[Adam]

if u have her as a friend she can see them only way for her to not see them is to delete her

[sogy]

Good News - Its totally Possible
Better News - I have written a very detailed post exactly for this need.

http://sougat818-technical.blogspot.com/...ivacy.html

Have a nice time Facebooking

Update: Just Read your Update on older post. You can block someone from viewing your Wall altogether. I suppose that would be enough. But actually the older post have the privacy setting set that she can see them. And you can't change privacy settings for a post that has been posted. If you have any more information to give or want to ask something you can comment in my blog. I'll surely reply