Well a mil is a thousandth of an inch. I mostly use LW for doing architectural modeling and have it set to English units - feet, inches.
It's 1 um in metric, which is one millionth of a meter. No wait, that can't be right. Hmmm.. a micron is a millionth of a meter.
Antonia is ~70cm tall in LW.

I can try some of those tests but it's going to have to wait until tomorrow. I have to go somewhere now though.
I'll see if I can figure out anything more tomorrow. Meanwhile if you have any suggestions, just type them up and post them. Or you could email if you want to. :-)

Meanwhile I'll find out what a um is. I know it's teeny. ;-)