I was asked to play the part of Jesus in a church a few years ago. I don't do religion, so I kept my mouth shut and watched for lightening storms...

Just tell her to do the praying and then silently meditate, or agree with her, since positive thoughts are effective, as the placebo affect shows.

Ugh... Had a kid ask me to read his bible kids book with him. I told him that he doesn't want me to read it with him and I get, "But how are we supposed to learn about God?" I had to ignore him because his hypocritical mother was just sitting there waiting for me to answer so she could yell at me. She knew I was an atheist and was looking for an excuse to pick a fight with me.

I don't disrespect my knowledge for anyone's beliefs. A 10 year is most definitely old enough to hear that not everyone believes. If she asks why you don't believe, tell her that is something that you'll share with her as an adult or she can ask her parents. Plus, there is always a possibility they're the ones who put her up to it.

A lot hinges on Mommy Dearest or Danny Dimly. If my brother or sister had the gall to put that in my lap, I'd ask the nearest sibling if they wanted to answer my niece. Because they should know I'd start the prayer with the tooth-fairy.

I'd go a step farther I think. Perhaps add to the experience for her. Have a tea with her, a few minutes of hand holding, and then the devotional and maybe sing a soft song together?

Let her pray and sit with her and respect her beliefs. Being an atheist/agnostic does not give you the right to disrespect her beliefs. A ten year old is very impressional. If your niece ask, when she's older, explain to her your beliefs.

Why not? is her childhood.

Sit with her and let her pray. Respect her beliefs. When she is a bit older you can tell her why don't pray. I am fairly sure if she is praying her parents have led the way, and I would try to be a good aunt and not piss off her parents. Not at age 10, but when she's older if you have a good relationship.

Personally I would decline.