Is it weird for teenagers and adults to be friends?

[Quietsoap487]

At the church I go to, we have small group leaders. For example, there is a small group leader for the ninth grade boys, ninth grade girls, tenth grade boys, tenth grade girls, and etc. Every Sunday, we break into small groups and spend fifteen minutes with them. We discuss what we learned about in church, what's happening in our lives, and etc. I'm fifteen years old, and my small group leader is thirty-seven years old. We began talking on Facebook about anything and everything (nothing inappropriate, though) multiple times a week. Sometimes we message each other, post on each other's walls, comment on each other's pictures/statuses, and etc. We have been talking since July, and have became very close because of Facebook. I'm still shy around her at church, but talk to her often on Facebook and am very open and honest with her. Also, my best friends have Duchenne Muscular Dystrophy. She is bringing them a used Xbox and used video games for the Xbox. She has never met them but really wants to, so when she brings them (ages fourteen and sixteen) the Xbox, we're going to 'hang out' for a while as well so she has the chance to meet them. Now, I have two questions:
1. Is it weird for us to be 'friends' both on Facebook and in 'real life'?
2. Is it weird that she's going to meet my friends and 'hang out' with us for a while?
We're both girls, so it's not an inappropriate relationship or anything. Just wondering.