Oh she would definitely notice and defo make a HUGE drama out of it too, just a little extra something to add to the chip on her shoulder. I can't begin to tell you how big a drama it would become...
I've been nosing on FB's privacy settings and I can actually add her to a seperate friends list, i.e. create a new one and then use that list to block her from seeing certain things...for example add her to a list and then use that list and stop it from seeing status updates or stop it from seeing comments I make on others profiles or stop it seeing photo's so might try that and see if I can put a halt to it that way...kinda make her think I'm just not as active or something. Easy way out but more saving myself the headache of a full on family bust up.