I am glad to read your SD is in therapy and has you.
My adopted children's biological maternal grandmother (whew, lol) made them leave within an hour of their 5 day visit because the dog was acting up with them there. I certainly understand your frustration. Even stranger was my daughters comment when I went to pick them up.....she said "I am really mad at you". I asked "why?" She said "because You didn't even defend us to her." Ugh
She and I were always super close until she turned 18. My friends, family and I have been completely shocked to see how she has been treating me the past 2 yrs. I am told that it is not that uncommon. I am the safe one to take her anger at her bio mom out on. I wish I had kept her in therapy longer then I did.