Facebook has developed new algorithm for their advertising machine. Here it is:
Like-:
Whenever you like something on Facebook, it shows on your friend's timeline too, only if they have subscribed to your profile. So, if you like coke, it shows up on your friend's timeline when you actively click on Like button of coke's page or post, Facebook checks if your friends like it too or not by showing the same 'Liked' post or page on their timeline with your name. This helps Facebook ad machine to recognize how many users are there who likes coke, where do they live, what their behavior is and with whom they share it. Because Facebook knows the 'suggestion cycle' difference between strangers and friend. Because if stranger likes coke, you will not care, but if your friend likes coke, then you will give some ****, because he or she is your friend & it matters to you.
- In your case your friend would have turned on 'Get Notification' for your profile, so whenever you actively do on Facebook, she gets the notification with your name and activity.
- Also, she may would have put you in hers 'close friend' list, that's why she also get to view your activity on her timeline.
- Also, if Facebook got paid from that particular page owner, then the person who wrote 'Hey, Nice Post' might have seen it and commented on it.
- If she turns of notification, she won't be getting any notification of your profile activity.
- If she removes you from the close friend list she won't be able to see your profile activity on her timeline.
Share-:
It's a simple task, if you share some post or activity, it shows on your friend's timeline, if they have subscribed to you. Most of the time, if the Page have paid Facebook to target some particular people, then your friend might be seeing it as a 'Suggested Post', with your name on it, i.e. -> [Name] shared coke's post
So, these are some few reasons she might be able to see exact post you liked or shared. I hope I cleared your doubt.