I do not have gay family, nor hiave I been in a similar situation.
You are correct in seeing this as wrong. Were I in your shoes, I would:
Be supportive of your sister, but let her know that she is wrong. The KEY is that she has ‘decided’. It was a decision, not a predisposition. Same-sex physical relationships and unions are wrong, not to celebrated or allowed into a families life.
I would welcome her to my home, not her partner. The child? Part of me says No, it is of no blood to you, the child could/would be used as a pawn to crack open your door. Part says to welcome the child, it is innocent, not deserving of rejection in all this. That is a hard spot. Prayer, lots of prayer.
I would welcome her to my home, not her partner.That's another way of saying "don't welcome her". I can't imagine anyone accepting such a rude excuse for an "invitation".
Listen to the second part of you then, because unlike the first, it makes a bit of sense. It's a child, and it's going to need a loving family just like every other child. Ostracizing a child because you don't like decisions the parents have made is wrong on every level imaginable.
Your concern about the child being used as a pawn to
crack open AUJenn’s door is well founded. Not only
that, she can expect requests and well publicized
disapproval if she refuses to allow her children to visit
the other two women’s household unaccompanied, or
to refuse their offers to babysit, etc. That’s the way
it’s going to be.