My granddaughter had an umbilical cord bone marrow transplant at 15 months old. She never made enough white blood cells, and then her bone marrow began failing and the red blood cell count began to fall, despite nightly shots of stimulating factors.
Roni had O neg blood, karyotype 46, XX. Her donor was a little boy (46 XY), with type A+ blood, matching about 70% of her immune markers. Now, Roni's blood is A +, 46 XY. She had to have her shots again, because all of the (too few) white blood cells that were exposed to the immunizations where destroyed by the chemotherapy that killed the rest of her bone marrow. From the transplant on, all cells that are derived from the bone marrow will be those of the donor.
(I think she can be a Baptist preacher, now, but, I'm not sure :) )
The DNA of her other cell lines, including her ovaries, heart, skin, etc. are her's - 46 XX. But, wherever cells grow from stem cells in the bone marrow, from now on, they will be from the donor.
It turns out that this sort of transplant of stem cells has always occurred in nature: we've found that mothers of boys may have male cells in the thyroid, liver, etc.
Fascinating! This story line will show up on Crossing Jordan or Law and Order, if it hasn't already!
God Bless your granddaughter. May she have a long and happy life.