A couple of bits of news, both bad.
I took the car to the nearest Ford dealer for an examination and diagnosis. I got the chef d'atelier rather than the grease monkey, and he decided it was a sticky rear caliper. Up on the lift, the wheel would hardly turn until he gave it a good kick, and froze again when he applied and released the brake. Easy job, huh? Pistons half out, squirt of brake cleaner, rub with a toothbrush, job done.
Main dealer - won't do quick clean-ups. New pistons needed - but the pistons are not available as a separate assembly, so I have to fork out for a whole new caliper. A whole new sodding caliper, at a total cost, fitted, with all taxes paid, of €642. That's over six hundred bloody quid. I took the step of phoning the Ford dealer near home and talking to a friendly mechanic there, and the problem is common (apparently) and the price, while much more than they would charge, is about right for France. Yes, French prices are waaaaaaaaay more than British, to an extent that amazes even British Ford people. And the mechanic advised (as I would have advised someone else in the circs) that, as the fault was brake-related and therefore safety-critical, that I should have it done and swallow the pill. I was tempted to risk it and fix it myself at home, but caution prevailed and I am booked in for Monday. That's the moules marinière budget out of the window, then,
And the second little ray of sunshine was Anna walking alone through the Reception of the campsite and tripping on a very small step, falling, and smacking her face on a concrete wall. She now looks as if she has gone 12 rounds with Tyson - I have seriously never seen a more spectacular black eye. All in all, it could have been far worse, as her back was completely unaffected, so we are laughing about it now. (The real worry is any damage to the spine could mean nerve damage and the rest of her life in a wheelchair, so I think we got off lightly here.) But everyone we meet, I have to explain and try not to look guilty. And I am not letting her out alone again - it's worse than living with a toddler.
I have a photo on my phone, which I will post in due course if she misbehaves again. It's a threat.
Thanks for all the comments, folks. Much appreciated.