when my mother passed away, she left a will and in it stated that "everything" went to me and my daughter, but with no caveats or ratios (50/50, 60/40).
in order to assure that my mother's wishes were met and that my daughter was given her appropriate "share", my attorney recommended that she have a Guardian ad litem to represent HER interests. while i certainly had no evil intentions, and in fact made "her" share last until her first year of college (she was 9 when my mom died), having an impartial 3rd party to represent her legally was just the right thing to do.