NBSB is what J/A/J/S referred to their alliance as and the more I have contemplated Shelly's behavior since the throw down with Jordan the more I think this is where some of her(delusional) attitude of vicitimization at the hands of Jordan comes from.
For those of us raised in the South during Shelly's generation, most frequently by southern parents, manners were of the utmost importance. It didn't matter if you didn't get along with your classmates, workmates, or best friend's spouse you were polite. It didn't matter what was happening between two coworkers, students or families there was always a varnishing of politeness. This still exists to some extent in the South but it is not as ingrained as it once was, I tend to believe my (Shelly's) generation is the last generation that this was beaten into.
In Jordan, Shelly saw someone else who had been raised to be polite and smile at her frenemy no matter what. That is where the comment about Jordan's mother must have come from, of course Shelly is forgetting that Mom's are Mom's, Northern or Southern, and when they see what they percieve as hurtful behavior directed toward their child, manners can go out the window and Tiger claws are grown.
In general though this veener is important to people in the South. I know I am from the south and was raised exactly like this, you work with someone you absolutely can't stand, you still invite them to the party at your home and treat them exactly the way you would treat your closest coworker. It doesn't matter what kind of "politics" is happening, it doesnt' matter how intense the disgust you feel for another You MUST be polite.
Hell, in alot of southern families this can extend to your cousin, who ought to be in jail for how he/she has treated her ailing parent. You are still polite until the ailing parent has passed and then you can write off the skezzy cousin, BUT not UNTIL THEN.
My gut tells me is Shelly is upset that Jordan will not abide by this "code of manners".