My personal opinion is not to give her any money for the deductible. She drove the car, she had the accident and yes, you are separated living in separate quarters. She left and wants to live on her own, well...it's time your w learn what life is all about. She knows that if she cries a sob story, you'll rescue her.
You can advise her that money is tight and that you, too, are in the same boat when it comes to a budget and needing groceries and paying child support, as well as rent, etc. Time to man up and just tell her that you are not liable for any debts that she incurs.
Oh, she'll be angry for a while...but guess what? She'll learn to respect you more if you set your boundaries and stick to them and allow her to learn what life is about and be held accountable for her actions. You are not her father and it's not your place to bail her out every time she screws up, especially while separated.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
