You may be able to finangle it with console commands.
If the path you are on, set variables, you'll need to zero those out, then jump to the event you want to follow.
I could look into it a bit later today if I remember.
edit: could use info on what was last event you saw with her, so I can use that to track down the event.
edit2: as well as samanthas current max possible love and sub stats [i could use that to gage which event you are on]
it should be easy to find out the event id, so i can just give you the command to jump to path d, however, that may leave path c quests still open? I'm unsure.
Btw, newgame+ could be ok, as you keep your starting perks
.