Rhona f
Scottish and English: of uncertain derivation, apparently originating in Scotland sometime around 1870. The spelling Rona is also found, and it is probable that the name was devised as a feminine form of RONALD (SEE Ronald) or an Anglicized form of Raghnaid (see RAGNHILD (SEE Ragnhild)). It has also been suggested that it may be associated with the Hebridean island name Rona (cf. AILSA (SEE Ailsa), IONA (SEE Iona), ISLA (SEE Isla)); the spelling would then have been altered by association with RHODA (SEE Rhoda).
First names dictionary. 2012.