Thanks for taking the time to give me such detailed info Dark Knight!
Ford rang her back this week and sent parts to the dealer. So today she has taken the car to the dealer and they have fitted these parts.
She got home without any problems, which given recent outings is an improvement, so hopefully the problem has been resolved. If not then the info you have posted will come in very handy as I think she may well have had enough!
I'll let you know if the problem has been resolved with todays actions.