I don't have all the answers and I feel for you and your daughters. But I also feel for your wife right now. This situation is not a picnic for her either.
I can state with absolute confidence that her kids are my kids and my kids are her kids. There are no step kids in this family. We are all together and we fight hard for one another. Mary and me, along with her ex and his wife, are all together when it comes to the kids. We actually sit down together and talk about our kids. We listen to each other and everyone's view point is considered. I have yet to deal with a situation regarding our kids that we did not come to absolute agreement on. Along with this, I must say that Mary is the catalyst for our collective parenting. Again, she is so amazing.
She feels as though her own kids are being attacked, and while she is docile and not easily provoked, she is currently excellerating to all-out bitch mode on my kids behalf. My ex-wife fears her, LOL. Thanks for thinking of Mary. I will tell her.