In the beginning of the Torah, it seems like men are having the children all by themselves. This man sired that child, that man sired another, and so on. This probably spoke to the status of men in society at the time in terms of the child’s identity.
By the time of Sarah and Abraham, both parents are mentioned. After Sarah dies, the Torah says that Abraham sired Isaac, but does not mention Sarah. I do not think that the Torah is ignoring Sarah, but emphasizing that Abraham still acted like a parent to Isaac after some difficult situations that could have ended their relationship.
Sarah’s death caused Abraham tremendous grief, but also a bit of guilt. If you remember, Abraham never told Sarah that he was taking Isaac to be sacrificed. She never would have permitted this. There is a tradition that Sarah was told by another that Abraham took Isaac away, and she died of a broken heart before she had a chance to find out that the sacrifice never occurred.
I also have to imagine that Isaac started to feel distanced from his father after being tied up and almost killed by him. That would drive a wedge between anyone.
Abraham could have distanced himself from Isaac. He could have used his grief as an excuse. He may have subconsciously distanced himself because he felt he hurt his son. Instead, the Torah is telling us that Abraham remained engaged with Isaac in his life, and still acted like a father.
Their relationship may have been awkward and they did not speak as much as before their traumas. Nonetheless, Abraham never gave up on being a father.
So many people in their sadness cut themselves off from those who love them and need them. So many parents, grandparents, other relatives and friends cut themselves off from people they think they hurt or let down.
We are never going to be perfect, and we are never going to handle everything really well, especially when we are not at our best. Our loved ones, though, do not need us to be perfect. They just need us to be there for them and to be concerned for them.