Am thinking that since the mother is a "meth addict" that maybe she wasn't/isn't emotionally available for her daughter. Nothing worse for "young children" to be left to just "exist" and not feel loved. When a mother isn't emotionally available, I think it is wondeful that the "father" is available.

Divorce hurts children..And maybe the "father" is over doing it by giving his daughter extra attention; I see no harm in this. As for his daughter sleeping with him, I again see no problem with this. AM sure, when the "fire" from the divorce settles and the father gets custody, the little girl "in time" will want her own space/bedroom.. Just my opinion