Character Customizer (Version 4)

Take a look at the Animation map in Content Examples. UE4 supports run-time retargeting with meshes that have differing proportions to cut down on repeated animations.

Edit: Just to test I re-assigned the female skeletal mesh to the male skeleton and the only issue I can see is a major pinch on the wrists.

FemalePinch.PNG

No FBX but I can confirm that it works with animations that support the Epic skeleton.