you all have started.
I don't have much advise... As a survivor of sibling abuse (brother), , and friends with multiple survivors of female sibling abuse...I just want you to know that has some of its own challenges... and too go gentle on both of you.
I hope you can find the help you need and keep Ken singer's words in mind..." this is not a DIY project".
Richard Gartner s book is a great start, regardless of the sex of the perpetrator. Consider also Mike Lews book... and a bit further down the line kens book.