Share plugins using widget text, not main body text

All the share plugins I’ve tried pull text from a widget I have on the top of my pages. I want it to pull text from the body of the post, or better yet, I’d like to define the text to be shared in each post/page. Can any one help, please. You can see exactly what I am talking about if you go to my page http://www.LibertyLifeWorks.com

Thanks
joe