His dad is a certified scumbag, but she deals the killing blow for him, as an assassin and her actual job being the hit job on his dad. I presume she isn't a member of any other organization and might be an independent hitwoman because she doesn't seem to be returning to any group's base or reporting to some boss.
Without knowing anything else, I assume page 3 is what happens after the 75 days is up. They go into hiding as fugitives for an eventful 75 days, and he gets arrested at the end of it, I've no idea what happens to her.