I just did a used oil analysis of Motorcraft 5w20 on my V6 Fusion (see the used oil analysis section)... came back AMAZING. I've had two Duratec's in the past and both were very easy on oil (one in a Mazda 3, the other in a Mazda MX-5). 5k intervals on Motorcraft should be no problem (unless she has some crazy driving style). If you want to run a synthetic, Mobil 1 or Pennzoil Platinum/Ultra get my votes.
Approx $15 for Motorcraft... $25 for your choice syn (assuming you use Wal-Mart + 5qt jugs). Stick with the Motorcraft filters... $3-$4 at Wal-Mart and they have the bypass valve at the threaded end per Ford spec. FL-910S is the model you will need. Oh, and in regards to air filters... I will say that when I recently changed both of mine, I went for a WIX filter -vs- stock, and I feel it is a MUCH better made filter. Much more snug fit & seal in the airbox.