SD's mum has only contacted her daughter 4 times in the last 7 months, and hasn't seen her since April.
JMO but wouldn't it serve everyone best if you all just kept on with your lives and make decisions for what happens in January when you get to January.
Has your SD been to Alateen? Maybe it's time for her to start getting this kind of support. How wonderful it is that you and your H are there for her. Alateen could give her some additional support to deal with whatever happens.
(((HUGS))) to all.