Jim Dixon said:"Though I'm no expert on Scottish diction, I think the spelling should be "cannae" and "grannie.""

I appreciate what you are saying, Jim. I'm pretty sure that despite living in Scotland all my life (in my fifth decade) and having a deep love and abiding interest for Scots language, I'm not that much of an expert either.

However, I'd agree with Andy on this one - "cannae" is ambiguous as a pronunciation guide, while "canny" is pretty clear. Having said that , I think "grannie" and "granny" are more or less equivalent.

Maybe a compromise would be be "..canny shove yer grannie.."?