That is just horrible that she had to endure that in her previous life...bless her heart...that brought tears to my eyes reading..
You did the best thing with reassuring her...I think her behaviour would be normal. Just think in human terms anyone enduring violence would have flashback as well...she is never going to forget, I am sure..but I bet she knows that it wont happen again...she has your assurance and protection now...
Give her a big hug from me...you khow I have a special place for her in my heart just because of her name..lol..