Focus reverse problems

[hiland]

My wife has a 2012 German Focus sports with auto transmission, today she parked on a fairly steep hill and went to reverse, all that happened was that the engine lost revs and the car kept going forward, she was in a situation where there was another vehicle parked in front and she had to reverse to get out. I eventually got it to move backward by using both the hand and foot brake to hold position and rev the engine and it jerked back a couple of times so she could drive out, when I finished getting enough clearance to drive out the iinfo screen said transmission overheat, she drove it without any problems for the rest of the day, She has had several small auto cars and never an experience like this, is this a common problem?, and what is the cause/, or better still is there a fix?.