I think that Pip had mixed feelings about his sister's death. On the one hand she brought Pip up "by hand" meaning she hit him quite a bit. On the other hand Mrs. Joe was his sister and she was a large part of his roots. Pip is aware that his lack of sorrow for his sister. He, however, feels guilty about this lack of sorrow, which certainly says there was a connection for Pip.
Whatever my fortunes might have been, I could scarcely have recalled my sister with much tenderness. But I supposed there is a shock of regret which may exist without much tenderness. Under its influence (and perhaps to make up for the want of the softer feeling) I was seized with a violent indignation against the assailant from whom she had suffered so much; and I felt that on sufficient proof I could have revengefully pursued Orlick, or any one else, to the last extremity.
Pip is slowly coming to realize the importance of family even if it is through the lens of guilt. It is for this reason he vows to visit more often.