In case you haven't spotted it

[frozen-jelly.livejournal.com]

Just was re-checking the friends page and realised Arthur's post has a new comment, which goes someway to explain how Minerva managed to keep such a privileged position despite her previosu close links to Dumbledore etc :
http://alt-arthur.livejournal.com/1372.html?thread=8284#t8284

Comments

[queenbookwench.livejournal.com]

It seems like the Order would have taken the time for her to learn Occlumency before stepping into that role--it seems like she would have been exposed while taking the Dark Mark otherwise, because V. routinely probes the minds of his followers.