Luckily my family just believed in God but were not actually religious. Most of my family now are either spiritual or agnostic from my switch to atheist and our discussions. I did marry a Christian and we each agreed to raise our child with both beliefs and let him decided. He is now 11 and she is completely shocked he is an atheist.
My brother is the only one that I came out to. My mother died without knowing, that would have broken her heart. Most of my family are connected to my Facebook page, so there is no way that they don't know, because I am pretty blatant about it - eh, they really never challenge me about it; I think they know better than to press the issue. They aren't ok with it, but they never ask.
Here in the UK it is more the norm than having belief I would say so not really a question. Anybody who puts anything random down to god is consuderrd a bit querky if not downright weird.
It is very interesting to see how different cultures react. I am Latina, as you probably know, the vast majority of Latinos follow a form of Christianism. My parents and brother are Catholic and believe it or not I am the weird in my family. They know I am agnostic, they repeact it but we don’t even talk about it because the times we have done so it has become a big issue, specially between my mom and me.
@MoralesHuman the church of england, the main organised church, with the queen as its head is officially part of the government system but in reality it has no real influence and church attendance is very low.
We have a largish Catholic community where things are taken more seriously and lots of other small more active groups. But most people who identify as Church of England couldn't care less and are basically agnostic without really thinking about it.
Fewer and fewer bother to marry in church and christening are pretty rare let alone confirmations
As an aside my mother now in her eighties is now a vitiluent atheist though her values and ethics remain essentially christian.