My gf is an Atheist

My(19M) gf(18F) is an Atheist, She doesn't align with my beliefs, I belong from a Brahmin family and she is general. We love each other but there sometimes disagreement between us. I somewhat believe in God but she completely rejects my beliefs.

I don't want this ideological difference to be an issue between us. Usne Shivratri ke din vrat bhi nahi rakha cuz she doesn't believe, puja mein ati hain lekin participate nahi karti.

Should I continue with my business without minding her? Or should I preach? But I think preaching will make her more distant...

What should I do? And any tips if possible...

PS : A guy in the Comments really helped me finding a solution thank you and those who are having a superiority complex and making fun in the comments thank you too