Big job, but sure, it can be done. Depending on where you live (you didn't say) there are probably better and worse times of the year to attempt this.

I've never gotten an established camellia to survive transplanting, the rather sparse roots are like wires and when you cut them back the bush just dies. So if you don't have the apparently required "special skills" for moving camellias I wouldn't bother. Especially at this time of the year.

A 4' camellia doesn't sound too daunting... I've heard of much larger camellias getting successfully transferred, though wihout knowing where you are, I don't know if this is the best time of year to attempt it. If your friend is not in a hurry to get the camellias out of her yard, there are steps y'all can take to make the move less stressful.

There are many good online resources about how to move established camellias, and about how to espalier your new plants.

Good luck,

Virginia

If your goal is an espallier, it's far easier to start with a young plant. To create the espallier form, the main trunk and branches must be small & flexible enough to be able to shape them against a trellis or wall.