How to tell my mom I don't care about her FB nonsense?

[lfh1213]

Perhaps you should start "Telling It Like It Is". Politely, of course:

"Mom, much as I'd like to chat with you about this, I have a deadline facing me. I must get to it. I'll call you when I find a few spare minutes."

Then, of course, you must call her back, but have a list of topics by the phone ready to begin and/or change the topic if needed.

Additionally, it might be wise to advise your mother that FB is a very dangerous place to post trash-talk. It's too available for people to see. Posting about your boss seems like a risk to your job, should he find out! She can block your boss's sister, or change her page if she wants rid of her. Or perhaps the sister should make her own page...?