I don’t know how to split a single post list into 3 columns/widgets without duplication, probably a way to off-set each query.
If I had to do this I might try using post tags
“page1” “page2” “page3” tagging each post with the page you want it to appear on.
Then query each tag in it’s own php widget in your footer. But you’d have to customize your tag template, or create one that shows one post per page.
Not very elegant but should work.