hmmm... I don't know much about Swissy's (but I'm sure someone else can take that angle), but it sounds to me like (and I'm merely speculating here) she may have been concerned that people were messing with her territory and she may have been a little anxious over all the mulling around.
I think the core of the problem is dominance, though. She should respect you and your family members and not charge for no real reason. I think punishing her by kenneling her probably didn't teach her much, it may have just made her more anxious to be separated from what she thought she needed to protect or defend.
Maybe a better idea for next time would be to keep her on a leash until everyone arrives, take her around to meet everyone so they can greet her and be friendly so she doesn't feel threatened. That way, if she does growl, you have her on the leash so you can correct her immediately. Keep her on the leash next to you until you feel confident that she feels comfortable. If she acts out, put her back on the leash and correct her behavior, but don't remove her from the situation.
Does that make sense?
p.s. I love her name. I was born in Sioux Falls and went to college there!!