They'll fit anything I'm sure... lol

I don't have LaRoo so I don't know what size she is, but you can scale them to fit anything and then just parent them to the figure.

I did this image using MallenLane's Plant Pixie as one of the pop up images... I actually conformed the wings to the figure and then scaled them down until they looked like they were about the right size... if the figure you want to use them with has a chest body part you can always try conforming them first to see if they fall into place properly... if they do, then just leave them as a conforming figure, if not, then instead of conforming, parent them to the figure.