Yes.
The poem was written in response to seeing his cousin, Lady Wilmot Horton, at a ball. She is his cousin by marriage, through a man named John Wilmot, governor of Ceylon..
> (3) These stanzas were written by Lord Byron, on returning from a ball-room, where he had seen Mrs. (now Lady) Wilmot Horton, the wife of his relation, the present Govern of Ceylon. On this occasion Mrs. H. had appeared in mourning, with numerous spangles on her dress – L.E.
From _The Complete Works of Lord Byron: Reprinted from the Last London Edition_.