Update
I've been good and left SitR alone for a week, but this afternoon I couldn't resist having a teensy peek. Just raising the edge of the lid for a second or two.
Fermentation has subsided. It's hard to tell but the brew looks like it's a lovely warm mahogany colour. Best of all, the aroma that hit me was gloriously beery, nothing "off" about it at all.
And then I sealed it up again. I won't be able to do anything with it until Wednesday, when it will have been fermenting for 11 days. I hope that no harm will come to it in the next three days and that all it will do is settle, but any reassurance that I'm doing the right thing would be very welcome (I've been having a bad few days and all reassurance is particularly welcome at this time!)