Really? I think you scream into a pillow and somehow they hear it. Like riding a unicorn
What you seem to be doing is learning to co-parent. Considering three daughters, that may come in handy right?
Each of you is behind the wall and trying to co-parent. Previously you had a familiar way to do that, but now you don't. You need to re-learn how to do that and this is what it looks like, if you ask me.
Your daughter is obviously upset about things in general. While the three daughters may become very close with all of this, it's not likely that all three will handle things the same way.
Teen years are difficult enough without a suicidal mom, a dad who's grieving the loss of the marriage and family and just being a teenager.
As for doing something wrong... You cannot do something wrong when it comes to a MLCr. Except not let go of your expectations of "normal" interactions. You can be open to the interactions if they are pleasant and respectful. If they are not, do not let it continue. Outside of that, nothing can be done "wrong" with a MLCr that I'm aware of.
AJ
"Our lives begin to end the day we become silent about things that matter" MLK Put the glass down... "Yesterday I was clever so I wanted to change the world Today I am wise, so I am changing myself."