I am so sorry to hear what you are going through. Unfortunately, I had to "walk away" from my SD when XWW and I divorced. Same years almost: 3 - 15yo. We had a very good relationship apart from the normal teenage girl angst. I realized that I was fighting a losing battle and SD would pay the price if I tried to win at all costs. XWW and her family filled SD's head with all sorts of untruths and they had the inside track. I hope you fare better with SS.
SD is now 23 and a psychology grad student. I hope she chooses to re-engage with me when she feels comfortable doing so.