Her name, meaning "the beautiful (or perfect) woman has come,"I am not sure why they wear it around their necks. She had a great deal to do with re-instating the egyptian religion after her husband tried to bring it down and have a single god to rule over them. She isnt known very well but historians are trying to piece an idea of her together. Here are some links that might be able to help you further.
www.homestead.com