My girlfriend is financially responsible, but her credit score is being negatively impacted by her ex-husband. He kept the house when they separated, but apparently she was never removed from the mortgage, which she discovered upon receipt of a notice of non-payment from the bank. It seems he has abandoned the property and stopped paying a couple months ago, so she's collecting these derogatory marks. Her FICO has dropped from the low 700s to the low 600s (so far...). Hopefully it doesn't go to foreclosure. (Also, hopefully the court can issue her documentation with which she can contest the account/derogatory marks and have them removed.) Because of this recent plummet, I want to help shore up her credit.
Surprisingly, this is not a post where I ask about cosigning to help her open a new account. She does not currently have the intention of opening new accounts, though she does not have many in her history.
We are in a serious relationship that we are confident will culminate in marriage.
1) General question
What can I do in either the short or long term to bolster her credit?
It is my understanding that some credit card issuers will report history for authorized users, but I would not add her as an authorized user to my cards until we are married.
I'd reckon having a current mortgage on her report would be beneficial, but I don't think there's a way to simply add her to my existing mortgage without refinancing the whole thing. (This also wouldn't happen until we are married, anyway.)
2) Specific question
Is there any harm in adding her as a cosigner to my auto loan?
I expect to purchase a vehicle soon, and I will probably finance it, especially if a 0% promotion is available. Would I face any negative impact by adding her as a cosigner? Could it lower my chance of approval? Could having her associated with one of my accounts affect my future creditworthiness somehow? The only risk I see -- albeit very low IMHO -- is to her: she would be trusting me to make payments on time (as I have done my whole life), but I don't see a risk to me. Even if not, for the sake of her credit, is this even worth doing? I do not need her income for loan approval. This is only to add more positive activity to her credit history.
No derogatory marks
1 mortgage, 5 credit cards (active)
3 auto loans, 2 credit cards (closed)
A few late payments
1 mortgage (delinquent)
1 auto loan, 1 student loan, 1 credit card (active)
1 student loan (closed)
Thanks for your advice and recommendations. Sorry that I'm verbose.