SPOILER ALERT!! I think I need to see the film again! I also don't seem to recall anyone saying who the father of her son was and what had happened to him. Given that the shot which killed her brother had been from an IRA gun, I assume her mother had been a double agent for a long time? Too many things didn't add up for me; annoyingly I can't find a break down of the plot anywhere as I need it to be spelled out to me [I can never understand James Bond films either, so I go into this sort of film without even attempting to make sense of them..the two exceptions being Donnie Darko and The Prestige].