Is there anything in the text to suggest what kind of relationship Hamlet had with his mother before his father's death?

This is interesting. I really don't think there is much here that we can take from the past. Many critics feel that Hamlet had an Oedipus thing going for his mother. This means that he really loved his mother! The rational is that he is obsessed with her marital and sexual habits for much of the play. Hamlet's relationship with Ophelia is heavily mixed up with his feelings for his mother. Sure it's creepy but then again it was also royalty back then. If there was a falling off, I don't think it happened until after he found out about her relationship with uncle. Was Hamlet just angry that he could never get a chance at scoring with his mother? I'm really not sure and it's a little disturbing to give too much thought to.