Recording solo harp is a bitch - your signal chain has to be very clean - and very quiet. I've used
the Shure SM-81's before and those worked very well. When I do it again, I'll probably try the Marshall MXL-603S's (from about a 4' to 6' distance), or the Behringer ECM8000's (in pretty close). Some points to consider:
The pedals can be noisey, so getting the mics about 6 feet in the air or more can definitely help. Put the harpist on a 4' x 4' square of plywood to direct some of the sound up in the air. Try both X/Y, ORTF, NOS, and even wide A-B spacings to see which works best in your room.
Also, try putting the harpist in the long corner of the room to cut down some of the other room nodes, and then adjust the mic distance, to balance out the one major node you've created (by putting it in the corner).
What didn't work well was the Neumann TLM-103, an AKG 414BULS, an AKG C3000, EV CS-15, and just about every other mic in my damn locker. The woman brought 3 different concert size harps and a medium Celtic harp to the studio.
It took a whole day just to decide on the mics and the placement. Good luck; jazz harp will probably be a little easier, but not much.