I am atheist, but I have always allowed my children to make up their own minds. I took them all to a Unitarian Free Church when they were young. One of my children belongs to a Christian Fellowship Church but the other two seem more agnostic. Although I do not believe in a supreme being myself, I can't see why other people shouldn't if they gain some comfort from it.

I'd just be happy that my kids had had the opportunity to choose for themselves.

If they’re disappointed in you for believing in God, pray for them that God can change their hearts so they can see you differently.

I believe in God and so it's hard to say if the situation was in reverse.

I wouldnt be dissapointed. I'd think it was cute. "Awww. How adorable. She'll learn."

It depends upon the individual and what type of atheist they are. If they are the "Angry Atheist" or the "Online Troll" Atheist" they will be upset and disappointed. Most real Atheist probably wouldn't care as long as the child isn't trying to convert or condemn them, and had valid reasons for believing

Probably , I'm sure they love them anyway

It's your belief, they can't actually hate you for it.

Probably

I would disown my kid if it turned into a Christian.

A little bit yes. Nobody likes to see their children join a cult or get fooled into believing fiction. But it won't change my love for them.