I think your niece has a good point there. My politics are like hers. I have a cousin whose politics are like yours. I had to ask my cousin to remove me from her mailing list because i didnt like getting anti-obama jokes. I suppose we both think we are superior to each other (my cousin and i), but so what? We just know not to talk politics with each other.
Thats why they call it "friends and family". Dont let mark zuckerberg dictate your life!