So we've got a relatively simple design for her clothing.
Her shirt is an ordinary school shirt, albeit it has a "hole" in it, presumably going through her body to the other side. This could be achieved by "bunching" the shirt into a centre, sewing it to a layer under the shirt, with a dark hole painted into the middle. The effect would be replicated on the back.
And she's got a simple grey pleated skirt [it's hard to tell with Kikiyama's art, tbh.]
Then it's just socks.
The only thing that poses a problem is her arms, and potentially her bunches. Her raised bunch could probably be worked through by putting black wire throughout it, and using that to support it. Along with hairspray and various other goodies!
I'm assuming the best way to do her arms is via fake arms, possibly bought from a joke shop. These could be spray painted white to work with the rest of her colour scheme [she is a monochrome girl, after all, that's her name], and by painting my own limbs white, they could be attached via some kind of clear strap [invisible bra straps spring to mind, weirdly enough] to the elbow of the right arm, and perhaps under the left arm, with two arms coming out of the left shirt sleeve.
The final hand could be attached to the wig mesh via sewing through it and onto the wig mesh, or via pins. Not sure if it'd be too heavy for that, though.
One eye seems fairly normal, while the other leaks a kind of fluid. The face would be painted white with the overall colour scheme, so it might be advisable to make the fluid black. Preferably viscous.
The mouth would leak the same black fluid, too.