Well, here's an update, if anyone is interested:
The whole issue is now moot, as DS and her DH are now persona non grata over here at the Mr Kitty residence.
After yet another bout of calling and emailing me trying to get me to sign up, I finally sent her an email politely but firmly telling her to STOP with the mlm recruitment. It was not going to happen and I wanted to hear no more of it.
Well, a few hours later I received a hostile diatribe detailing every real and imagined fault I ever had....with some vile and disturbing accusations about politics thrown in besides. Though I was tempted to, I did not respond, even though my brother, who can't stand her, offered to pen a vitriolic response on my behalf.
Then, on election night, at around 11:30 pm after the election was called, Dear Sister's husband called me every five minutes until 1 am leaving hostile, vitriolic and insulting messages for me and my husband because we did not vote the way he instructed us to.
And.....now we're done.
P.S. I don't care what anyone's politics are. The issue isn't politics, but rather how one expresses one's opinions. My brother and myself, well, we are of different parties. We disagree on some things, agree on others, and agree to disagree on yet others. Yet, we can talk all day about it, debating issues, and it does not devolve into insults, name calling or threats - because we keep the debate solutions-based and refrain from using ad homonym and other types of arguments. We also acknowledge that all political parties have valid ideas and are just as American as all others. In other words, we keep it civil, and the discussions are truly a pleasure, unlike my sister and her husband, who prefer brow beating. This is about them personally, NOT their political persuasion.