I apologize for not coming back into my own thread sooner, but I haven't been able to spend as much time here as I want. To answer some of the posted points:
SWMBO took the middle ground in this whole debacle. She sees my point, but we both also agree that she (SWMBO) is in large part to blame for this, too. She has basically allowed both of her kids to get away with doing nothing around the house. To make a long story as short as possible, their father was killed when they were 2 & 5, so she felt that she needed to let them enjoy as much of their childhood as possible, which meant that she would take on all of the burden.
When I came into the picture, five years ago, I started to change things, especially when she asked me to move in with them. The kids see me as a step-father, and I treat them just like I do my own two kids. I was raised to have responsibilities, and see no reason why her kids shouldn't also.
Now, as to the daughter...I've mentioned in other threads that she's epileptic, which means that up until now, she hasn't been able to work OR drive. She has now gone the longest stretch in 12 years, when she became epileptic, with out a seizure. She IS looking for work, and now taking driving classes, but it's still slow going. And she's still lazy.
However, NONE OF THAT is a reason, IMO, for her to not help around the house, especially after the blizzard. As I stated in my op, between her mother and I, we are a surgeon's wet dream. Helping us would not have done a thing to set off any seizures. As of today, it's still a bit of a cold war scenario between us. Fortunately, and most importantly, it hasn't affected my relationship with SWMBO.