I think that checking the brake fluid level, as a matter of urgency, is called for.
If there has been a sudden and unexplained drop in level rather than the usual gradual fall which accompanies the normal wear of the pads, then the leak must be found and fixed before the vehicle is used on the road again.
Thanks both, glad I posted. The Ka is such a basic and primitive beast, I'd be surprised if the brake fluid reservoir is wired! However, DD and NC, your advice is much appreciated and has been passed on to daughter to check handbook and brake fluid before leaving for work in the morning.
Indeed it is wired on the Ka. I had to replace on my friends W reg and on my old MK4 Fiesta it is a very common problem that sensor gets stuck although that usualy causes no light to come on when it should :(.
Yes, you're right. Daughter confirms the presence of wires, making it difficult for her to remove the cap and check the level. This at least means she is looking at the right reservoir. I suggested she do what I usually do - rock the car and shine a torch at it. Is this the technical forum?