Thanks asterix and fuzzy. Things seen to have settled down. She's not over-grooming at all, and it was only very small tufts. I know what you mean, fuzzy: I did have a cat once who regularly had fights, and little scabby tufts would come out.
Now, what else can I think of to worry about, apart from our leaking washing machine, the Eurozone, UKIP, the York Arrow weather.....