My son is a senior and my daughter a freshman at the same university. They have always been very close growing up, until, it seems, my son's senior year in high school. From that point on, he acts as if he resents her and rarely contacts her. He refuses to call her on her birthday. Once in a while in my presence, he will hug her and act as if he still loves her.

My daughter is heartbroken - she has tried persistently to keep up with him in person, via email, and Facebook, but to no avail. His life is replete with applications to grad school and an upcoming marriage. I have tried to explain to my daughter that perhaps his life is stressful and, being at a different time and place of transition than hers, he feels as if he does not have time for the relationship. She will see him in the cafeteria and he will not even return her hello. At this point she does not want to even attend his wedding; in her words, "That will probably be the last time that I see him and that he will ever speak to me and my heart can not take any more."

I do not agree with my son's attitude towards his sister. I have tried to broach him on the subject but was unsuccessful and greeted with hostility. In fact, he seems to have more regard for his in-laws than for his sister and I. Are there any solutions? Or do we just wait and hope that as time passes he will remember he has a mom and sister?

Please note that there were no traumatic incidences between my two children in the past; I am a single parent and the father's rights were terminated. My son spends an inordinate time each month (3000 minutes) on the phone with his grandfather (my dad), who relishes in this attention but (ny dad) does not seem to care how my son treats his sister. I am glad that my son has his grandfather as a male role model but at times I feel that my dad is aggravating the situation between my son and daughter and myself.