Dont want my sons to visit their great grandmother?

I understand your concern, which you are totally entitled to, but I think its about a different generation mentality... She is from a different mindset on how children should be parented. I mean, she was probably working at age 8. There were no child labor laws then, nothing to protect the child... Maybe if you talked to her about how you are feeling, and buy her some outlet plug protectors (!!!) she will see your side of this and then your children won't have to miss out on being with their great grandmother. What an amazing thing for them to get to experience. Not many people ever get to meet their "great" anything. Hope this helps and you can still include her in their lives.