for the residence your wife has a split basis......1/3 would be a carryover basis because it was a direct gift from your wife's cousin.....the other 2/3 depends on what happened first, the gift or the cousin passing away....if he passed away first then his 1/3 share got a stepped up to fair market value basis as of his death and your wife and the sister took that basis and then the quit claim gift would be a carryover from the sister to your wife and that basis would again be split because the sister's 1/3 was half gift which is a carryover and half inheritance which is fair market value as of the date of death.
