She's seen that I totally have her back and want the best for her but most of all for her to be well and happy. She has said her dad has blamed her for lots of things such as his failed relationships (3 in the past 12 months) problems at work and saying she is making him stressed and depressed. That's why she was suicidal.
Congratulations. This is a major breakthrough. She needs to see and feel the light for herself.
I am very close to someone who has been through this exact situation. Moved out with the DF who used her as a conduit to abuse the DM indirectly with the DD being emotionally abused at the same time. You can see this. You can’t point it out because she is being controlled and if you do it will be counterproductive. It is actually good that the tide is turning and she is seeing and experiencing for herself that he has now turned on her directly.
Keep calm, consistent, connected.
This approach worked for friend. Her daughter is home now and doing brilliantly.
She never directly pointed the finger at the XH to her DD because this would be inflammatory but she would say things like “how does that make you feel, do you think that’s fair, acceptable” etc. when the DD told her stuff. Her DD has now come through it. Don’t worry that throwing everything at it is not sticking - just prioritise the moments of connection you have with her in a very balanced and boundaried way. She absolutely wants you and is craving the routines, comfort, calm and kindness that you built in her childhood.
Know that - even if her behaviour looks otherwise.
It won’t be a straight line. You will have loads of other shit times - but log the moments that are good and hopefully see it settling over time. Manage your expectations - be realistic and think maybe by Christmas she will engage in therapy.
Don’t feed her dysregulation by becoming emotional yourself, don’t let her hijack your day or the rest of the family. Calm, calm, calm consistent boundaries, deadlines and consistent consequences. Don’t allow yourself to be emotionally triggered and bounced around the drama triangle from rescuer to persecutor to victim.
You job is to help her learn to self soothe so that she can identify and dial down stress to feel better inside and then behave better to herself and others and this is achieved by you being constantly being neutral, attentive, boundaried. As a PP said it’s called co-regulation (you can see the effects of co-reg with your X) - she will absorb your energy. She might need to learn some overt grounding techniques as well.
I read a great animal analogy of parenting in crisis recently - where we get triggered to extreme behaviours which are totally counterproductive - ostrich (obvious head in the sand) rhino (aggressive frustration, blame, attack and demand of the child) Kangeroo (overly engulfing, wrapping in cotton wool and keeping trapped in our pouch) jellyfish (where our inner triggered emotions are too transparent and destabilising for the child). All are unbalanced when we recognise ourselves like this we need to switch to either the St Bernard (solid, no drama, safe, predictable, reliable, plodding in through one foot in front of another) or the dolphin - attuned, responsive, role model, side by side, playful sometimes out in front, sometimes behind letting the calf lead the way.
This stuff sounds simple but it’s not always easy. If you can get some professional emotional support for yourself and take time to restore to cope through this difficult time as well as ensure your other child are prioritised.
She may have an underlying genetic MH issue (if her father does), she may have an early unresolved relational or physical trauma, she may have an undiagnosed neurodiversity, she may have an untreated physical / hormonal issue. She may not. She may have all of these compounding issues or she may have a combination of some.
But first off she needs emotional stabilisation which IMHO starts with her reconnecting with you, little by little and then over time you / she will have the perspective to investigate other potential issues.
You are further through this than you think if she knows her DF is dumping on her and she can articulate that to you. You have her back, always have had and that’s money in the emotional bank that he can’t drain and will begin to pay back.
Look after yourself OP. You are a wonderful mother in these truly trying circumstances.