WARNING: Extremme Spoilers afoot. Dont read if you dont want to know the full arc of the game and Spoilers about etc.
(SPOILER)Lucrecia is in stasis after the game that is all I know
(SPOILER)Vincent is redeemed but as you know Square they were very vague. The ending leads one to asssume Shelke and Vincent are together. There is no proof as to whot type of relationship they have. They could just be friends.
(SPOILER)Lucrecia was alienated by the though of being with Vincent after she somehow caused the events that led to the death of Vincents father, Grimiore. She got with Hojo and you now know what happened
If you read I told you not to so dont blame me.