Cheers for the replies people
She's been in touch with the dealers & they've offered to put a new lock set & keys on the car for her & sort out the individual locking but they haven't said anything to her about the door's locking on drive off.
I know on the focus and on a mondeo you can turn it on by having the ignition on and locking and unlocking the doors a few times then doing it with ignition off then turn on again and a beep is heard. That turned the doors locking when driving off on my mondeo and focus but i cant remember the sequence exactly. Maybe someone on here knows it?
I did however try it on my g/f's 6 month old fiesta and it didnt seem to work.
The option to change settings and stuff with the button on the indicator stock such as the hazards on hard braking and only one door opening instead of them all is only on certain models of fiesta. My g/fs zetec blue one has the button where as my mums tdci one doesnt.
Tho im sure it can be turned on other ways as said by holding buttons on the key fob.