Making editing easier for clients is a mixed blessing. There are a couple of ways of approaching it and it really depends on you as to what will work best. You can simplify the interface by using something like [Visual Composer or generate some pre-built templates using something like [URL="http://codecanyon.net/item/ether-content-builder-wordpress-plugin/1690784?WT.ac=search_thumb&WT.seg_1=search_thumb&WT.z_author=pordesign"]Ether Content Builder](http://codecanyon.net/item/visual-composer-for-wordpress/242431?WT.ac=search_thumb&WT.seg_1=search_thumb&WT.z_author=mixey). The other option is to use a template that uses a modular system where you can define the text in pre-set areas of the template. Alternatively you can just set a template yourself that uses 3 widget areas that can have their text replaced.
There are advantages and disadvantages to all the suggestions above and they aren't the only things you can do, but they are some reasonably quick fixes if your situation is limited to one client who wants this ability.