Totally forgot to add that info in! The story is set in the near future in the UK (torn between either Scotland or Wales at the moment, leaning more towards Scotland but still figuring things out), the character is 24 years old and would have been born around 2022. I think I was drawn mostly to Calluna because it seems plausible as a name and has the association with heather without it being obvious (Calluna vulgaris being the taxonomic name for common heather), and I'm not the biggest fan of Heather as a girl's name. Like you I prefer Heath on a boy to Heather on a girl.
Dod yn unrhyw beth
… solla solla solla