Jane Toombs’ 1976 The Fog Maiden is a standalone fantasy novel. If it were published today, I suspect it would be classified as urban fantasy/paranormal romance.
After the death of her father, Janella Maki was raised by her well-meaning but distant stepmother. Janella has no memories of her early past and knows even less about her biological parents. It’s a surprise when an uncle shows up to renew family ties.