You can't.
You cant
To be able to delete a group on facebook you must have created the group. You go onto the group and scroll down and on the left of the screen there should be a few words in blue saying leave the group or delete group. If its not there then look at the group setting and options at the top right or left of your screen. If you do not own the group scroll down to the bottom left and click block,report or just simply leave.
Actually, she does.
yes
search their name with a different facebook account.
how to block messages of unknown person on facebook
I believe it's the actually group called Facebook. However, I'm not sure. The facebook group has over 8,000,000+ people who have joined it.
In an open group on Facebook, anyone can see the group, who's in it, and what members post.
Yes
Yes you can
Yes
No