Okay, you seem to be understandably confused about several things. First of all, there’s really no such thing as ” a 47 string lever harp.” Most lever harps have 36 strings or less; a few go up to 40 strings.
More strings will not allow you to play more chromatic music. That’s a function of the mechanism. In this case, I think you mean you want a 47 string pedal harp. 47 strings is the usual range for a concert grand pedal harp. The Salvi Daphne is a pedal harp; i.e it uses a series of foot pedals to make the sharps and flats, unlike a lever harp where they are made by flipping a lever by hand.
The secondary harp market is actually pretty flooded right now. There are many, many instruments out there. If you don’t know what you’re looking at, there is also a lot of potential trouble out there.
Frankly, especially if she is “ambitious”, your daughter should be taking lessons from a competent teacher who can make all this clear and help you to find an instrument. Buying before you know what you really need can make for unhappiness later. Get a teacher first and go from there.