This past December I bought some DNA test kits through Ancestry.com for my sister, my father, and my paternal grandmother. I bought them to expand my genealogy research.
Nearly everyone wondered why I bought one for my sister. Most inquired, "Won't she have the same results as you, April?" To which I responded, "No, we're not twins." We will have a lot of DNA in common because we have the same parents but there will be some difference; we each got different DNA from our parents.
I had my father test his DNA because that will help me to determine if my matches are from my mother's side or my father's side. Also, all of his matches are my relatives.
I asked my grandmother to take the test for the very same reason; her results will help me distinguish grandma's side of dad's results from grandpa's side of the family. Grandpa is no longer with us and I have no communication with my mother so it makes the most sense to ask my sister, father, and Nanny.
Now that my sister's test and my father's test are both being processed I am starting to make some predictions as to how their ethnic profiles will differ from mine.
My sister will have different individuals whom she matches to but I think her ethnic profile will be the same as mine. I wished my profile would have shown some African ancestry and/or more European Jewish ancestry. I believe my ancestors to have been part of one of the largest slave trading families in England; not something I would be proud of but had I had any African DNA I would have pursued that line of ancestry a little more zealously. Also, I had suspected that perhaps my most maternal line was ethnically Jewish at some point because every search I do for their last name returns Jewish people but alas I am only 2% European Jew so I have my doubts that my Goetzs were Jewish. Maybe my sister's DNA will show a little bit of those ethnicity but based on my results, I doubt it.
As for my father, I suspect that he will be a little less Irish than I am and show a little more DNA from Great Britain. I make this guess based on looking at the ethnicities of his great-great grandparents who were mostly of English origin. If any African ancestry shows up I suspect it will be on this side of the family.
I don't believe my grandma, who we call Nanny, has not sent in her test yet. I am ok with that. I would kind of like to see Dad's results before hers. A total of 4 sets of results will be a lot to work through at once.
If I have to predict nanny's results right now, and I don't really have to do anything by the way :) , I would guess that she is even more Irish than I am. I am 44% Irish according to my DNA; according to my documentation of Nanny's great grandparents she is 50% Irish, followed by 25% German, her other two great grandparents were Swiss and French.
And so there you have my guesses. It will be a few weeks more until I know.