When I was a kid, I knew no adults that were not Catholic. I didn't believe and it left me feeling alone and like I had to work it all out on my own. It turns out there were some adults that didn't believe but they chose to remain silent. It would have helped me to know that they were there.

As an adult, I have always simply represented myself as agnostic. My family has become more accepting. I think it might have happened sooner had those other adults represented themselves honestly.

My advice is not to sell your beliefs, or lack thereof, but to represent them fairly and let others do the same. Give others another model to choose from.

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I generally just keep my thoughts to myself around religious people. If it is not going to change anything then why rock the boat?

How old is your sister?

With my kids, I told them what I believed when they asked but encouraged them to examine it for themselves. Critical thinking prevailed with them. They all identify as non believers.

Be honest with your sister.

That would be a difficult situation for me to be in. I grew up around religion.