Where to begin?

[Dawgs]

So I have a new situation that just came up yesterday that I could use some advice on. Promise this one is a little different...

So my own family has basically "disowned" my W. There is a birthday party in a few weeks for my nephew and my own SIL asked how the invitation should be made out - to just me and the kids? Or just the kids?

I told her that we ALL are coming because we are still working on us - yes, there has been a subtle shift in my W's attitude, etc. My SIL then answered that she wasn't welcome in her house, and if I did bring her then she would give my W a piece of her mind. I told her that even though we are having problems, my W is still my W until the divorce goes through (if it does) and until then she should be treated as such.

My own SIL has the holier than thou attitude. I told her not to make me chose, because they wouldn't like the answer. My W deserves respect, even if we are having problems. I told my SIL that if my W isn't welcome, then neither am I. I just do not know what to do. My kids love my nephew, but I strongly feel that they shouldn't go where my W isn't welcome. She is their mother, and yes, we are working on us.

I can't help but also think that this behavior may drive a wedge in my own family and cause my W to feel unwanted or angry, which could possibly hurt reconciliation. What does everyone think?