Get the Iona Inspirations book by Tina Tourin. There are two songs at least that have a piano/pedal harp part and a therapy harp part. They’d definitely sound good together! There are several more that could be played this way. There’s nothing too advanced on either harp or piano and they all sound more complex than they are. A CD is also included!
I find this true. I play the keyboard and a cousin of mine plays the harp. We tried to play together and it was a bit hard at first. The piano music was fine but it was hard finding the right tone for the harp. Well I guess we just need practice then.