I created a script that can be found here 'http://outboxed-dev.net/scripts/webflow/vertical-align.js'.
If you include it to your site and add a 'vertical-align' class to any element it will align it vertically (and horizontally) to its parent element as long as the parent has (offset) height.
http://outboxed-demos-dev.webflow.com/positioning/vertical-align is a demo page with nested aligned elements.
It will work for only one element so use it wisely.
100% Webflow friendly