Ask a landlord-tenant lawyer and get answers ASAP
It sounds like the tenant is simply lying to you about the BK to try and keep you from suing her for damages. If she hasn't filed anything, then you are free to try and run them through. Verbal doesn't mean anything legally.
And yes, you definitely need to send a written itemized list of damages to her last known address, which would be the property address if you don't have a forwarding address. This needs to be done within one month of her moving out and I would send it certified as well as regular mail in case she has a forwarding address. Also take lots of pictures of the property so as to document its condition..