Mystery Cholestasis Diagnosis??

My son is 5 1/2 weeks old.  At birth he was jaundiced and his bilirubin level was elevated.  He was on a bili bed for a few days until the indirect bilirubin level went down and the jaundice seemd teo clear.  Unfortunatley, his direct (conjugated) bilirubin level was still a little high and has been ever since.  We've been to a gastroenterologist who is now telling us he is fairly confident that my son has Cholestasis, specifically PFIC 3.  More test need to be done but at this point this is the most likely disgnosis in his opinion.  The funny thing is, my wife has been itching severely since giving birth.  She went to a dermatologist who ordered some blood work and found out that her bilirubin is also mildly elevated along with some of the same liver tests results as my son.  I know PFIC 3 casued by a genetic defect that could be passed on to my son from my wife but I still have questions.  Why did my wife's symptoms show up after delivery?  Could this be a delayed form of Cholestasis of Pregancy that happens to be affecting my son too?  Is there another possible diagnosis that would connect the two patients?  Could this go away on it's own in both mother and child?  We're not getting many clear answers on the connection between the two and we are worrying ourselves sick.