I played a concert last week on lever harp. My harp mover helper was out of town, and I had planned on playing my pedal harp. So at the last minute I changed the part in Marble Halls that is chromatic. I enclose that short section here for you to print and paste into your music. I took the piano accompaniment from 8notes.com and played it pretty much exactly as written, but pasted in the below adjustment.
I subscribe to 8notes.com – I find it very valuable for the oddball ensembles that I find myself involved in, and some are normal, like flute and harp! Here is the Marble Halls accompaniment in D. https://www.8notes.com/school/transpositions/pdf/flute/marble_hallsfl_u4.pdf
“I Dreamt I Dwelt in Marble Halls” or “The Gipsy Girl’s Dream” is a popular aria from The Bohemian Girl, an 1843 opera by Michael William Balfe, with lyrics by Alfred Bunn. It is sung in the opera by the character Arline, who is in love with Thaddeus, a Polish nobleman and political exile. – source: https://en.wikipedia.org/wiki/I_Dreamt_I_Dwelt_in_Marble_Halls