The key thing on my 04 fiesta is you have to hold the lock and unlock button on the fob till the car flashes the indicators (bout 5 secs) then it unlocks the doors individually and repeat the process if she wants to change back.

Is the "doors not locking on set off " not in an option somewhere on the menu? Has she had a thorough look? I took an 07 fiesta out for a spin and you could change all sorts - even stuff like if your hazards flash if you break heavily

Can't sort out the master one though Maybe they just gave her the wrong key?