What is proper for women?

[M. A. C. Newsome]

Actually, James, it is supposed to be the other way around. Clanswomen wear the sash from the right shoulder; wives of chiefs, chieftainesses, and colonels' wives wear a sash from the left shoulder. The Court of the Lord Lyon has a pamphlet describing this :
http://www.scotarmigers.net/pdfs/info-leaflet-7.pdf

Cheers,
Sandford

I have my own thoughts on the whole "ladies must wear their sash on the right shoulder, unless they don't" rule.
http://albanach.org/sash.htm

I think most ladies should wear their sashes on the left, unless they have a reason for wanting to wear it otherwise.