Nogranhere, want to add this to my earlier post to you (but can't because no edit button here, darn!)...
Some people don't know why their ac cut them out and others say they don't know because maybe they don't want to face what they did wrong or don't want to correct it (NOT saying that about anybody here). For example, one of my friends who is co is very warm and generous - but also very bossy. Her ds and dil asked her many times to stop trying to control their lives, but she wouldn't back off. Now she's co and saying, "Idk why!"
But in your case, imo, it's obvious that you really don't know. Not that I would doubt you, but it's clear because, based on what you've told us, dd seems very conflicted. This is on her, imo, not you. Unfortunately, that means there's not much you can do that I can see until she figures out what she needs from you.