Im not sure how to phrase what I want but basically: I just commented on a page and my MIL liked it. How do I stop that from happening? I don't want comments that I post coming up in the news feed. My status updates fine, even people we are both friends with, fine but I don't want everyone seeing my comments on other people's statuses.
if you go into your fb settings then there is a very complicated form showing who you want to see what, and when, and if the moon is a cresent then does that mean you want your arch enemy to see it or only a quarter of the posts from tuesday. euegh i know its not very helpful, but in privacy settings there is a whole load of crap you have to work your way through to sort it out! i gave up and barely use fb!
You can't stop it. If the post you're commenting on is visible to all, then it will come up in all of your friends' "stalker feed" at the top of the chat bar on the right.
The only way you can control it is to check when you comment what the little symbol is by your friend or the page's post, if it's a little world then everyone can see it, if it's a picture of two heads then their friends can only see it, if it's a little cog it means "custom" and you can sometimes hover over it (so for example if they've tagged someone it will say <friend> and <tagged person's> friends can see this).
If you only ever comment on posts which have privacy set to "friends" then people like your MIL won't be able to see it.