Seafoam is an additive that can be put in the pcv, crank, and gas to help clean and knock off sludge.(Found at all local auto parts store) Eh...I would say that you don't need to use the seafoam on the pcv and in the oil, because its such a new car, but it would be helpful to pour in the gas tank (just follow instructions).
Also, Don't know maintenance intervals on a focus but I would definitely recommend changing the fuel filter and air filter. I know on my year stangs you change the fuel filter every 30k. Find out the maintenance intervals and do all that is required. Other than that it would help to check air pressure on the tires and check to see the spark plugs are still good.
Since the car is so new I would bet on the filters and possibly on the fact she may be driving differently or in different conditions lately. Good luck and if what is said in this thread doesn't help put an update and we can go from there.
