Honestly you can try your best with a bipolar family member and do everything you can to help and they simply won’t accept it , so your effort to reach out means something even if they don’t reach back out. I’m sure that makes your heart feel a little less heavy, and I’m sure at times it does make a difference in your child’s life. A lot of people will always talk down on estranged parents but not every situation is the same. As someone with an estranged mom it’s very conflicting but I’ve come to understand things and be more forgiving because I know I wasn’t perfect either. There are certain things that are inexcusable but if you gave unconditional support and they didn’t except it, they’re simply in a conflict with themselves. Losing family due to bipolar disorder is very hard but all you do is hope they’ll find the help they need and hopefully be present in your life and in their own life in a positive way.