Will an intervention work? If my daughter and I leave will this feed into my wife's abandonment issues to where leaving with allow her to say, "There you go... . everyone I ever loved leaves me." How can I bring to light just how sick she really is? Is there anything (aside from saving myself andd my daughter) that I can do to at least show her or shock her into seeing truth? We are at the end.
Short answer is No!
spratrbo, she needs to get help when she is ready - who knows when that would be. Denial is rife.
Leaving could trigger her yes - however right now, how can you protect you and D17? Be mindful spratrbo that many things may trigger her abandonment fears - not yours or D17 fault.
You are not responsible for her happiness - you are however responsible for your own and D17

Be kind to you