Thanks everybody for your good wishes and help! I talked to my sister yesterday and she says that the top is bowing toward the soundboard. I'm not sure if this type of problem can be repaired, but it doesn't sound too promising. As I said before, I probably won't be actually picking up the harp before summer, but when I do, I'll check with some of the harpmakers you all have suggested.
BTW, her new harp (a Steen, I think) is wonderful. She played a little for me on the phone. She's very happy with it, but it will take a little getting used to, as it's bigger than her old harp, so middle C has moved. The string tension is different, and it also has some synthetic gut strings and the bass strings are wound nylon, so there is a totally different feel and her fingers are complaining a bit. I'm looking forward to seeing it.
thanks again, jeffp