Modification DC Diana Ankle Mod?

(Kinda image heavy)
So I am now the proud owner of a Doll Chateau Diana, and for those who may not know, she has two sets of legs - one pointed fantasy style, and one human with feet.

Call it my blissful ignorance (this is one of my first DC dolls), but I assumed the ankles on the human legs would be jointed - I was wrong.
So that you can swap them over easily without extra elastic, both sets have the hook attach to a bit in the knee, and the human feet and ankles are static.



Therefore, I was wondering if anyone had perhaps already modded the ankle so that it can be moved? It has sculpting to look like it is jointed, so a pretty easy guide for where to cut and add the joint.

As it isnt hollow all the way through, would there be a way to just string it to the part just above the ankle (will add an image what I mean below)


Even if it means making a new ball-joint for the ankle, the legs are just so tiny it would be impossible to drill all the way through it, and then you'd need to restring her every time you wanted to change her legs. Doing something like the above means less of that, but still super tiny I guess XD

So if anyone has done this, something similar, or could recommend any way of going about this it'd be greatly appreciated! If I do go through with the mod I'll make sure to document it here.

(for full view images, they're on imgur here!)

 

She takes a bit of concentration to stand up as is, but that might just be me XD She has a habit of the legs spinning then falling over, which I think is down to her stringing anyway, but I think if her ankles are jointed then theres more room for better balance